﻿<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.1 20151215//EN" "https://jats.nlm.nih.gov/publishing/1.1/JATS-journalpublishing1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" dtd-version="1.1" specific-use="sps-1.9" article-type="research-article" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">abcimg</journal-id>
<journal-title-group>
<journal-title>ABC Imagem Cardiovascular</journal-title>
<abbrev-journal-title abbrev-type="publisher">Arq Bras Cardiol: Imagem cardiovasc.</abbrev-journal-title></journal-title-group>
<issn pub-type="epub">2675-312X</issn>
<publisher>
<publisher-name>Sociedade Brasileira de Cardiologia</publisher-name></publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.36660/abcimg.20240053i</article-id>
<article-id pub-id-type="publisher-id">abcimg.20240053i</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Original Article</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Left Ventricular Function and Myocardial Longitudinal Strain Analysis in Patients With Chagas Disease: Case Series and Systematic Literature Review</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0002-5894-1167</contrib-id>
<name><surname>Borges</surname><given-names>José Victor da Nóbrega</given-names></name>
<role>Conception and design of the research</role>
<role>acquisition of data</role>
<role>analysis and interpretation of the data</role>
<role>writing of the manuscript</role>
<role>critical revision of the manuscript for intellectual content</role>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="corresp" rid="c1"/>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0004-3041-0083</contrib-id>
<name><surname>Leila</surname><given-names>Samira Abdel Correia</given-names></name>
<role>Conception and design of the research</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<role>critical revision of the manuscript for intellectual content</role>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0002-9043-1033</contrib-id>
<name><surname>Machado</surname><given-names>Manuella Guedes da Nóbrega</given-names></name>
<role>Conception and design of the research</role>
<role>acquisition of data</role>
<role>statistical analysis</role>
<role>critical revision of the manuscript for intellectual content</role>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0004-5539-936X</contrib-id>
<name><surname>Babu</surname><given-names>Kiran Sooraj Thirukonda Jegadeesh</given-names></name>
<role>analysis and interpretation of the data</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0001-5319-0248</contrib-id>
<name><surname>Patel</surname><given-names>Karma Jashvantbhai</given-names></name>
<role>analysis and interpretation of the data</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<xref ref-type="aff" rid="aff5"><sup>5</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0001-7136-5830</contrib-id>
<name><surname>Shah</surname><given-names>Kavya Hiteshkumar</given-names></name>
<role>analysis and interpretation of the data</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<xref ref-type="aff" rid="aff5"><sup>5</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0003-5030-8863</contrib-id>
<name><surname>Takkasila</surname><given-names>Mahitha Reddy</given-names></name>
<role>analysis and interpretation of the data</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<xref ref-type="aff" rid="aff6"><sup>6</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0005-6269-0136</contrib-id>
<name><surname>Shaik</surname><given-names>Abdul Majid</given-names></name>
<role>analysis and interpretation of the data</role>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<xref ref-type="aff" rid="aff7"><sup>7</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0005-0829-1521</contrib-id>
<name><surname>Shaikh</surname><given-names>Muhammad Ahmed</given-names></name>
<role>statistical analysis</role>
<role>writing of the manuscript</role>
<role>critical revision of the manuscript for intellectual content</role>
<xref ref-type="aff" rid="aff8"><sup>8</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0003-3584-6500</contrib-id>
<name><surname>Khandekar</surname><given-names>Ninad</given-names></name>
<xref ref-type="aff" rid="aff9"><sup>9</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0006-5021-0446</contrib-id>
<name><surname>Burra</surname><given-names>Sahithi</given-names></name>
<role>analysis and interpretation of the data</role>
<role>writing of the manuscript</role>
<role>critical revision of the manuscript for intellectual content</role>
<xref ref-type="aff" rid="aff10"><sup>10</sup></xref>
</contrib>
<aff id="aff1">
<label>1</label>
<institution content-type="orgname">Universidade de São Paulo</institution>
<institution content-type="orgdiv1">Instituto do Coração</institution>
<addr-line>
<named-content content-type="city">São Paulo</named-content>
<named-content content-type="state">SP</named-content>
</addr-line>
<country country="BR">Brazil</country>
<institution content-type="original">Universidade de São Paulo, Instituto do Coração, São Paulo, SP – Brazil</institution>
</aff>
<aff id="aff2">
<label>2</label>
<institution content-type="orgname">Hospital Israelita Albert Einstein</institution>
<addr-line>
<named-content content-type="city">São Paulo</named-content>
<named-content content-type="state">SP</named-content>
</addr-line>
<country country="BR">Brazil</country>
<institution content-type="original">Hospital Israelita Albert Einstein, São Paulo, SP – Brazil</institution>
</aff>
<aff id="aff3">
<label>3</label>
<institution content-type="orgname">Clínica Central de Diagnóstico</institution>
<addr-line>
<named-content content-type="city">Vilhena</named-content>
<named-content content-type="state">RO</named-content>
</addr-line>
<country country="BR">Brazil</country>
<institution content-type="original">Clínica Central de Diagnóstico, Vilhena, RO – Brazil</institution>
</aff>
<aff id="aff4">
<label>4</label>
<institution content-type="orgname">Sri Ramachandra Institute of Higher Education and Research</institution>
<addr-line>
<named-content content-type="city">Sri Ramachandra</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Sri Ramachandra Institute of Higher Education and Research, Sri Ramachandra – India</institution>
</aff>
<aff id="aff5">
<label>5</label>
<institution content-type="orgname">Gujarat Medical Education and Research Society</institution>
<institution content-type="orgdiv1">Medical College &amp; Hospital Valsad</institution>
<addr-line>
<named-content content-type="city">Valsad</named-content>
<named-content content-type="state">Gujarat</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Gujarat Medical Education and Research Society, Medical College &amp; Hospital Valsad, Valsad, Gujarat – India</institution>
</aff>
<aff id="aff6">
<label>6</label>
<institution content-type="orgname">Kasturba Medical College Manipal</institution>
<addr-line>
<named-content content-type="city">Manipal</named-content>
<named-content content-type="state">Karnataka</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Kasturba Medical College Manipal, Manipal, Karnataka – India</institution>
</aff>
<aff id="aff7">
<label>7</label>
<institution content-type="orgname">Kakatiya Medical College</institution>
<addr-line>
<named-content content-type="city">Warangal</named-content>
<named-content content-type="state">Telangana</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Kakatiya Medical College, Warangal, Telangana – India</institution>
</aff>
<aff id="aff8">
<label>8</label>
<institution content-type="orgname">Jinnah Sindh Medical University</institution>
<addr-line>
<named-content content-type="city">Karachi</named-content>
<named-content content-type="state">Sindh</named-content>
</addr-line>
<country country="PK">Pakistan</country>
<institution content-type="original">Jinnah Sindh Medical University, Karachi, Sindh – Pakistan</institution>
</aff>
<aff id="aff9">
<label>9</label>
<institution content-type="orgname">Government Medical College and Hospital</institution>
<addr-line>
<named-content content-type="city">Thiruvananthapuram</named-content>
<named-content content-type="state">Kerala</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Government Medical College and Hospital, Thiruvananthapuram, Kerala – India</institution>
</aff>
<aff id="aff10">
<label>10</label>
<institution content-type="orgname">Osmania Medical College</institution>
<addr-line>
<named-content content-type="city">Hyderabad</named-content>
<named-content content-type="state">Telangana</named-content>
</addr-line>
<country country="IN">India</country>
<institution content-type="original">Osmania Medical College, Hyderabad, Telangana – India</institution>
</aff>
</contrib-group>
<author-notes>
<corresp id="c1"><label>Mailing Address:</label> <bold>José Victor da Nóbrega Borges</bold> • Instituto de Assistência Médica ao Servidor Público Estadual, Clínica Médica. Avenida Ibiapuera, 981. Postal Code: <postal-code>04084-009</postal-code>. São Paulo, SP – Brazil E-mail: <email>josenborges@gmail.com</email></corresp>
<fn fn-type="edited-by"><label>Editor responsible for the review:</label><p>Marcelo Tavares</p></fn>
<fn fn-type="conflict"><label>Potential Conflict of Interest</label><p>No potential conflict of interest relevant to this article was reported</p></fn>
</author-notes>
<pub-date publication-format="electronic" date-type="pub">
<day>01</day>
<month>10</month>
<year>2024</year></pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2024</year></pub-date>
<volume>37</volume>
<issue>3</issue>
<elocation-id>e20240053</elocation-id>
<history>
<date date-type="received">
<day>07</day>
<month>06</month>
<year>2024</year>
</date>
<date date-type="rev-recd">
<day>29</day>
<month>07</month>
<year>2024</year>
</date>
<date date-type="accepted">
<day>18</day>
<month>08</month>
<year>2024</year>
</date>
</history>
<permissions>
<license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/" xml:lang="en">
<license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
</license>
</permissions>
<abstract>
<title>Abstract</title>
<sec>
<title>Introduction:</title>
<p>Left ventricular dysfunction as an independent predictor of mortality in Chagas disease. Global longitudinal strain (GLS) is an emerging echocardiographic modality with possible incremental value in early detection of cardiac involvement.</p>
</sec>
<sec>
<title>Objective:</title>
<p>Compare left ventricular function with multiple echocardiographic parameters between patients with the indeterminate and chronic forms of Chagas, and perform a literature review.</p>
</sec>
<sec>
<title>Methods:</title>
<p>In this observational study, 11 patients with a confirmed diagnosis of Chagas disease were evaluated. Individuals were distributed as follows: five with the indeterminate and six with the chronic forms. Conventional echocardiographic evaluation was followed by GLS measurement.</p>
</sec>
<sec>
<title>Results:</title>
<p>The mean left ventricle ejection fraction left ventricular ejection fraction (LVEF) was 33 ± 2.88, and the mean GLS of the left ventricle was −10.76 ± 2.20 in the chronic form as compared to 57.80 ± 6.49 and −17.34 ± 3.82, respectively in the indeterminate group. Contractility was reduced in segments of the inferior, inferoseptal and anteroseptal walls in both groups. These segmental alterations in the indeterminate group may be attributed to early myocardial damage from inflammation and fibrosis, even before significant left ventricular dysfunction is evident.</p>
</sec>
<sec>
<title>Conclusion:</title>
<p>Analysis of longitudinal strain in the indeterminate form has potential incremental value to the conventional analysis of ejection fraction when compared to patients with chronic Chagas cardiomyopathy, especially with individual segmental analysis, but the impact and clinical significance of these techniques are still unknown.</p>
</sec>
</abstract>
<kwd-group xml:lang="en">
<title>Keywords</title>
<kwd>Chagas Cardiomyopathy</kwd>
<kwd>Global Longitudinal Strain</kwd>
<kwd>Left Ventricular Function</kwd>
</kwd-group>
<counts>
<fig-count count="6"/>
<table-count count="10"/>
<equation-count count="0"/>
<ref-count count="36"/>
</counts>
</article-meta>
</front>
<body>
<sec sec-type="intro">
<title>Introduction</title>
<p>Chagas disease is one of the leading causes of tropical disease in the New World, with a higher burden than any other parasitic disease in the Americas.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> It is caused by infection with <italic>Trypanosoma cruzi</italic> (T. cruzi), a hemoflagellate protozoan parasite primarily transmitted by triatomine bugs, which feed on human and animal blood by biting on exposed areas. From the feces of the bugs, the parasite passes through these breaks in the skin or mucosa causing infection. Rarely, it may be transmitted congenitally via organ transplantation or through contaminated food and water.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> The different routes of transmission vary between geographic areas. First described in 1909 by Carlos Chagas, after whom it was named, Chagas disease was initially largely confined to Latin America where it is endemic.<sup><xref ref-type="bibr" rid="B3">3</xref></sup> Though vector transmission has been controlled to an extent in formerly endemic areas, with current migration trends, the prevalence has also increased in the United States, Europe and Japan.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> In 2019, the global prevalence of Chagas disease was estimated to be 6,469,283, an 11.3% decrease in prevalence in the preceding three decades from 1990. However, it was accompanied by an increase in prevalence in non-endemic countries. Spain had the largest absolute increase in estimated cases, followed by the United States and Italy.<sup><xref ref-type="bibr" rid="B5">5</xref></sup> This increase is mainly due to the population movement of already-infected individuals from endemic areas in contrast to the rarity of vector-borne transmission in non-endemic countries.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> Only 16 infections were presumably acquired by autochthonous, vector-borne transmission in the United States from 1955 to 2012.<sup><xref ref-type="bibr" rid="B7">7</xref>,<xref ref-type="bibr" rid="B8">8</xref></sup> Polymerase chain reaction (PCR) testing is the most sensitive test in the diagnosis of acute Chagas infection, including monitoring of the organ transplant patients from T. cruzi infected donors and immunocompromised patients.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> To confirm chronic Chagas disease, at least two serological antibody detection tests with different methods are required.<sup><xref ref-type="bibr" rid="B10">10</xref>,<xref ref-type="bibr" rid="B11">11</xref></sup> Indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and hemagglutination are most commonly used.<sup><xref ref-type="bibr" rid="B12">12</xref>,<xref ref-type="bibr" rid="B13">13</xref></sup> In the acute phase, patients are often asymptomatic or present with mild symptoms such as fever, fatigue, and rash. In contrast, the chronic form usually presents with gastrointestinal manifestations and, most seriously, cardiomyopathy, including heart failure, arrhythmias, and sudden cardiac death (SCD). Left ventricular dysfunction in an independent predictor of mortality in Chagas disease. Subclinical manifestations often precede systolic dysfunction. In the indeterminate phase, despite the absence of clinical heart disease, myocardial involvement can be detected through imaging modalities. Studies suggest that early inflammatory changes and fibrosis primarily affect the inferoseptal, inferior, and anteroseptal segments, which may explain the segmental contractility alterations observed in our study. Global longitudinal strain (GLS) is a non-invasive modality derived from bidimensional speckle tracking echocardiography (STE).<sup><xref ref-type="bibr" rid="B14">14</xref></sup> Assessment of STE along with conventional echocardiography has shown to detect subclinical left ventricular myocardial strain abnormalities even before a profound reduction in left ventricular ejection fraction (LVEF) in Chagas cardiomyopathy.<sup><xref ref-type="bibr" rid="B15">15</xref>,<xref ref-type="bibr" rid="B16">16</xref></sup> This technique emerges as a significant predictor of adverse cardiovascular events in patients with the indeterminate form of the disease.<sup><xref ref-type="bibr" rid="B17">17</xref></sup></p>
<fig id="f3">
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf00.tif"/>
<attrib>LVEF: left ventricular ejection fraction; GLS: Global longitudinal strain; LV: left ventricle.</attrib>
</fig>
</sec>
<sec sec-type="methods">
<title>Methods</title>
<p>A cross-sectional observational study of 11 patients with confirmed diagnosis of Chagas disease was conducted at a tertiary care specialized hospital in Brazil. Patients underwent detailed history, physical examination, resting electrocardiogram (ECG), and conventional bidimensional echocardiography with Doppler followed by GLS analysis using speckle tracking. Patients were evaluated using echocardiography to assess segmental contractility. Segmental contractility was specifically analyzed in the inferior, inferoseptal, and anteroseptal walls due to their known vulnerability to early myocardial damage in Chagas disease. Previous studies have indicated that inflammation and fibrosis predominantly affect these regions, even in the indeterminate phase. Advanced imaging techniques, such as speckle-tracking echocardiography, have shown these segmental dysfunctions in asymptomatic patients, highlighting the early impact of the disease on the myocardium. Participants had an average age of 76.36 ± 6.26 years, and written informed consent for clinical data usage was required for each individual in the study. The patients were classified as indeterminate (45%) and cardiac (55%) forms of Chagas disease.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> The patients with Chagas cardiomyopathy were classified as stage B1, B2, C and D.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> B1 is defined as structural changes as seen on ECG or echocardiography with normal global ventricular function and no symptoms of heart failure. Stage B2 shows structural cardiomyopathy with ventricular dysfunction but no present or past symptoms of heart failure. Stage C is defined as patients with ventricular dysfunction and present or past symptoms of heart failure (all New York Heart Association [NYHA] classes), and stage D is treatment-refractory heart failure requiring specialized interventions. Patients underwent serologic confirmation by anti-T. cruzi enzyme-linked ELISA (Ortho Clinical Diagnostic, USA) and indirect hemagglutination assay (IHA) (Polychaco, Lemos Laboratory SRL, Argentina). Echocardiography was performed using Philips Epiq 7C with a 3.4 MHz sector transducer. Measurements for left ventricular parameters were made according to recommendations by the American Society of Echocardiography and the European Association of Cardiovascular Imaging.<sup><xref ref-type="bibr" rid="B19">19</xref></sup> LVEF was calculated by the modified Simpson&apos;s biplane method using the apical four and two-chamber views. Left ventricle segmental and longitudinal strain analysis were conducted using the QLAB system (Philips, Netherlands). A scoping review of the literature was performed on major medical sciences databases, including Pubmed and Scopus. Keyword inclusion criteria was selected for the following: Chagasic cardiomyopathy and left ventricle GLS. The results were filtered to include full-text case reports of humans with Chagas disease written in English. A total of 25 records were obtained during the initial search. Two reviewers screened the titles and abstracts to determine if they met the inclusion criteria. During the screening, 12 records were excluded. A total of 13 records proceeded to the full-text assessment. Four reviewers assessed the content of the case reports to determine if they had enough information about the patients and their diseases. Baseline characteristics and echocardiographic parameters for the patients enrolled in the study are presented in <xref ref-type="table" rid="t1">Table 1</xref>.</p>
<table-wrap id="t1">
<label>Table 1</label>
<caption><title>Baseline characteristics and echocardiographic parameters for the patients enrolled in the study</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="5%">
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Patient No.</th>
<th align="center" valign="middle">Age (years)</th>
<th align="center" valign="middle">Body surface area (sq meter)</th>
<th align="center" valign="middle">LVEF (%)</th>
<th align="center" valign="middle">LA volume index (ml sq meter)</th>
<th align="center" valign="middle">LV mass (g)</th>
<th align="center" valign="middle">LV ESV (ml)</th>
<th align="center" valign="middle">LV EDV (ml)</th>
<th align="center" valign="middle">LV GLS (%)</th>
<th align="center" valign="middle">ANTSEPT LS (%)</th>
<th align="center" valign="middle">ANT LS (%)</th>
<th align="center" valign="middle">ANTLAT LS (%)</th>
<th align="center" valign="middle">INFLAT LS (%)</th>
<th align="center" valign="middle">INF LS (%)</th>
<th align="center" valign="middle">INFSEPT LS</th>
<th align="center" valign="middle">E-e’ ratio</th>
<th align="center" valign="middle">LVSd (mm)</th>
<th align="center" valign="middle">LVDd (mm)</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="center" valign="middle"><bold>1</bold></td>
<td align="center" valign="middle">74.5</td>
<td align="center" valign="middle">1.698</td>
<td align="center" valign="middle">31</td>
<td align="center" valign="middle">79.51</td>
<td align="center" valign="middle">277</td>
<td align="center" valign="middle">127</td>
<td align="center" valign="middle">186</td>
<td align="center" valign="middle">-14.2</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-17</td>
<td align="center" valign="middle">20.4</td>
<td align="center" valign="middle">51.6</td>
<td align="center" valign="middle">60.8</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>2</bold></td>
<td align="center" valign="middle">71.58</td>
<td align="center" valign="middle">1.555</td>
<td align="center" valign="middle">28</td>
<td align="center" valign="middle">58.96</td>
<td align="center" valign="middle">185.28</td>
<td align="center" valign="middle">152</td>
<td align="center" valign="middle">195</td>
<td align="center" valign="middle">-7.1</td>
<td align="center" valign="middle">-5</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-4</td>
<td align="center" valign="middle">-7</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">38</td>
<td align="center" valign="middle">55.8</td>
<td align="center" valign="middle">62.2</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>3</bold></td>
<td align="center" valign="middle">67.66</td>
<td align="center" valign="middle">1.674</td>
<td align="center" valign="middle">51</td>
<td align="center" valign="middle">34.29</td>
<td align="center" valign="middle">377</td>
<td align="center" valign="middle">116</td>
<td align="center" valign="middle">234</td>
<td align="center" valign="middle">-11.2</td>
<td align="center" valign="middle">-16</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">10</td>
<td align="center" valign="middle">49.5</td>
<td align="center" valign="middle">67.3</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>4</bold></td>
<td align="center" valign="middle">67.16</td>
<td align="center" valign="middle">1.664</td>
<td align="center" valign="middle">65</td>
<td align="center" valign="middle">40.21</td>
<td align="center" valign="middle">310</td>
<td align="center" valign="middle">53</td>
<td align="center" valign="middle">152</td>
<td align="center" valign="middle">-22.2</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-24</td>
<td align="center" valign="middle">-26</td>
<td align="center" valign="middle">-21</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">13</td>
<td align="center" valign="middle">35.7</td>
<td align="center" valign="middle">55.7</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>5</bold></td>
<td align="center" valign="middle">78.33</td>
<td align="center" valign="middle">1.73</td>
<td align="center" valign="middle">33</td>
<td align="center" valign="middle">62.41</td>
<td align="center" valign="middle">366</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">190</td>
<td align="center" valign="middle">-9.8</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">31.33</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">61.5</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>6</bold></td>
<td align="center" valign="middle">83.58</td>
<td align="center" valign="middle">1.791</td>
<td align="center" valign="middle">34</td>
<td align="center" valign="middle">41.2</td>
<td align="center" valign="middle">302</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">190</td>
<td align="center" valign="middle">-12.1</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">19.75</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">61.4</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>7</bold></td>
<td align="center" valign="middle">77.83</td>
<td align="center" valign="middle">1.492</td>
<td align="center" valign="middle">62</td>
<td align="center" valign="middle">23.13</td>
<td align="center" valign="middle">209</td>
<td align="center" valign="middle">49</td>
<td align="center" valign="middle">149</td>
<td align="center" valign="middle">-18.5</td>
<td align="center" valign="middle">-23</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-16</td>
<td align="center" valign="middle">9.8</td>
<td align="center" valign="middle">34.6</td>
<td align="center" valign="middle">55.3</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>8</bold></td>
<td align="center" valign="middle">85.5</td>
<td align="center" valign="middle">1.528</td>
<td align="center" valign="middle">35</td>
<td align="center" valign="middle">52.28</td>
<td align="center" valign="middle">257</td>
<td align="center" valign="middle">133</td>
<td align="center" valign="middle">204</td>
<td align="center" valign="middle">-9.9</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-7</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-12</td>
<td align="center" valign="middle">-4</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">24</td>
<td align="center" valign="middle">52.6</td>
<td align="center" valign="middle">63.4</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>9</bold></td>
<td align="center" valign="middle">70.33</td>
<td align="center" valign="middle">2.151</td>
<td align="center" valign="middle">49</td>
<td align="center" valign="middle">38.5</td>
<td align="center" valign="middle">287</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">194</td>
<td align="center" valign="middle">-15.1</td>
<td align="center" valign="middle">-17</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-12</td>
<td align="center" valign="middle">13</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">63</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>10</bold></td>
<td align="center" valign="middle">79.58</td>
<td align="center" valign="middle">1.932</td>
<td align="center" valign="middle">62</td>
<td align="center" valign="middle">27.33</td>
<td align="center" valign="middle">240</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">140</td>
<td align="center" valign="middle">-19.7</td>
<td align="center" valign="middle">-13</td>
<td align="center" valign="middle">-27</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-21</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">18</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">53.7</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>11</bold></td>
<td align="center" valign="middle">83.91</td>
<td align="center" valign="middle">1.637</td>
<td align="center" valign="middle">37</td>
<td align="center" valign="middle">58.84</td>
<td align="center" valign="middle">381</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">201</td>
<td align="center" valign="middle">-11.5</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle">65</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">63</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN1"><p>LA: left atrium; LV: left ventricle; LVEF: left ventricle ejection fraction; LV ESV: Left Ventricular End-Systolic Volume; LV EDV: Left Ventricular End-Diastolic Volume; LV GLS: Left Ventricular Global Longitudinal Strain; ANT-SEPT LS: Anterior-Septal Longitudinal Strain; ANT LS: Anterior Longitudinal Strain; ANT-LAT LS: Anterior-Lateral Longitudinal Strain; INF-LAT LS: Inferior-Lateral Longitudinal Strain; INF LS: Inferior Longitudinal Strain; INF-SEPT LS: Inferior-Septal Longitudinal Strain; E-e’ ratio: Ratio of early transmitral flow velocity (E) to early diastolic tissue velocity (e’) in echocardiography; LVSd: Left Ventricular Septal Diameter; LVDd: Left Ventricular Diastolic Diameter.</p></fn>
</table-wrap-foot>
</table-wrap>
<sec>
<title>Case Series Presentation</title>
<p>This cross-sectional observational study included 11 participants selected from a cohort of Chagas disease patients followed-up at a tertiary center in Brazil, with seven males (63.34%) and four females (36.36%) that were divided into chronic (55%) and indeterminate forms (45%). The mean age of the participants was 76.36 ± 6.26 years, with a mean age of 79.56 ± 5.16 in the chronic group and 72.51 ± 5.19 in the indeterminate group. In terms of classification of disease severity, patients in the chronic and indeterminate phases were classified as B1 and C stages, respectively.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> Clinical evaluation included detailed history, physical examination, resting ECG, and conventional bidimensional echocardiography with Doppler followed by GLS analysis using speckle tracking. Written consent was obtained from study participants, and even though no direct intervention was promoted, the proposed analysis was also approved by the institutional ethics review board. Patients of the indeterminate form were initially screened and tested for Chagas disease due to either generalized symptoms or suggestive epidemiological history without cardiovascular disease at the time of diagnosis. Patients of the chronic form presented with classic symptoms of heart failure, such as bilateral lower extremity edema, shortness of breath on exertion and paroxysmal nocturnal dyspnea. Three of the six patients (50%) in the chronic form were in NYHA class II, two patients in NYHA class III, and one patient in NYHA class I. One patient of the chronic form also had non-sustained ventricular tachycardia (NSVT) registered on 24-hour Holter monitoring (<xref ref-type="fig" rid="f1">Figure 1</xref>). The mean values for the echocardiographic and baseline parameters for all individuals are presented in <xref ref-type="table" rid="t2">Table 2</xref>. At the time of diagnosis, serologic confirmation by anti-T. cruzi ELISA (Ortho Clinical Diagnostic, USA) and IHA (Polychaco, Lemos Laboratory SRL, Argentina) were established. All patients were treated according to the most recent guidelines in cardiomyopathies.</p>
<fig id="f1">
<label>Figure 1</label>
<caption>
<title>Documentation of NSVT on 24-hour Holter monitoring for one of the patients with the chronic form of the disease.</title></caption>
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf01.tif"/>
</fig>
<table-wrap id="t2">
<label>Table 2</label>
<caption><title>Mean values of all participants</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variable</th>
<th align="center" valign="middle">Value</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">11</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Male (%)</td>
<td align="center" valign="middle">63.64</td>
</tr>
<tr>
<td align="left" valign="middle">Female (%)</td>
<td align="center" valign="middle">36.36</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Age (years)</td>
<td align="center" valign="middle">76.36 ± 6.26</td>
</tr>
<tr>
<td align="left" valign="middle">Body surface area (sq meter)</td>
<td align="center" valign="middle">1.7138 ± 0.1819</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVEF (%)</td>
<td align="center" valign="middle">44.27 ± 13.27</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LA volume index (ml sq meter)</td>
<td align="center" valign="middle">46.96 ± 16.16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV mass (g)</td>
<td align="center" valign="middle">290.11 ± 62.85</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVSd (mm)</td>
<td align="center" valign="middle">46.63 ± 9.13</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVDd (mm)</td>
<td align="center" valign="middle">60.66 ± 3.90</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV ESV (ml)</td>
<td align="center" valign="middle">105 ± 43.44</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV EDV (ml)</td>
<td align="center" valign="middle">185 ± 26.38</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">E-e&apos; ratio</td>
<td align="center" valign="middle">23.84 ± 15.48</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">ANT-SEPT LS (%)</td>
<td align="center" valign="middle">-13.20 ± 5.21</td>
</tr>
<tr>
<td align="left" valign="middle">ANT LS</td>
<td align="center" valign="middle">-14.90 ± 6.72</td>
</tr>
<tr>
<td align="left" valign="middle">ANT-LAT LS (%)</td>
<td align="center" valign="middle">-15.30 ± 6.45</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">INF-LAT LS (%)</td>
<td align="center" valign="middle">-14.63 ± 5.04</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">INF LS</td>
<td align="center" valign="middle">-12.20 ± 5.61</td>
</tr>
<tr>
<td align="left" valign="middle">INF-SEPT LS (%)</td>
<td align="center" valign="middle">-12.10 ± 5.68</td>
</tr>
<tr>
<td align="left" valign="middle">LV GLS (%)</td>
<td align="center" valign="middle">-13.75 ± 4.47</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN2"><p>LA: left atrium; LV: left ventricle; LVEF: left ventricle ejection fraction; LVSd: Left Ventricular Septal Diameter; LVDd: Left Ventricular Diastolic Diameter; LV ESV: Left Ventricular End-Systolic Volume; LV EDV: Left Ventricular End-Diastolic Volume; ANT-SEPT LS: Anterior-Septal Longitudinal Strain; LV GLS: Left Ventricular Global Longitudinal Strain; INF-SEPT LS: Inferior-Septal Longitudinal Strain; INF LS: Inferior Longitudinal Strain; INF-LAT LS: Inferior-Lateral Longitudinal Strain; ANT-LAT LS: Anterior-Lateral Longitudinal Strain; ANT LS: Anterior Longitudinal Strain; E-e’ ratio: Ratio of early transmitral flow velocity (E) to early diastolic tissue velocity (e’) in echocardiography.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>Echocardiographic analysis was performed and reviewed by two board-certified echocardiographers using Philips Epiq 7C with a 3.4 MHz sector transducer. Measurements were conducted according to the American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines.<sup><xref ref-type="bibr" rid="B19">19</xref></sup> LVEF was calculated by the modified Simpson&apos;s biplane method using the apical four and two-chamber views. Left ventricle segmental and longitudinal strain analysis were calculated using the QLAB semi-automatic system (Philips, Netherlands), which considered normal values &gt; −18%. The mean values for the echocardiographic parameters divided by groups are presented in <xref ref-type="table" rid="t3">Table 3</xref> (chronic form) and <xref ref-type="table" rid="t4">Table 4</xref> (indeterminate form). The end-systolic volume and left ventricular systolic diameter of a few patients were not obtained due to technical difficulties and, hence, not included in the data presented.</p>
<table-wrap id="t3">
<label>Table 3</label>
<caption><title>Mean values of participants with chronic form</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variable</th>
<th align="center" valign="middle">Value</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">6</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Age</td>
<td align="center" valign="middle">79.56 ± 5.18</td>
</tr>
<tr>
<td align="left" valign="middle">Body surface area (sq meter)</td>
<td align="center" valign="middle">1.6565 ± 0.1024</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVEF (0/0)</td>
<td align="center" valign="middle">33 ± 2.88</td>
</tr>
<tr>
<td align="left" valign="middle">LA volume index (ml sq meter)</td>
<td align="center" valign="middle">58.87 ± 12.60</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV mass (g)</td>
<td align="center" valign="middle">294.71 ± 72.51</td>
</tr>
<tr>
<td align="left" valign="middle">LVSd (mm)</td>
<td align="center" valign="middle">53.33 ± 2.19</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVDd (mm)</td>
<td align="center" valign="middle">62.05 ± 1.00</td>
</tr>
<tr>
<td align="left" valign="middle">LV ESV (ml)</td>
<td align="center" valign="middle">137.33 ± 13.05</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV EDV (ml)</td>
<td align="center" valign="middle">194.33 ± 7.005</td>
</tr>
<tr>
<td align="left" valign="middle">E-e&apos; ratio</td>
<td align="center" valign="middle">33.08 ± 17.13</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">ANT-SEPT LS</td>
<td align="center" valign="middle">-9.83 ± 3.54</td>
</tr>
<tr>
<td align="left" valign="middle">ANT LS</td>
<td align="center" valign="middle">-10.83 ± 4.16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">ANT-LAT LS</td>
<td align="center" valign="middle">-11.16 ± 5.38</td>
</tr>
<tr>
<td align="left" valign="middle">INF-LAT LS (%)</td>
<td align="center" valign="middle">-12.83 ± 5.49</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">INF LS (%)</td>
<td align="center" valign="middle">-8.33 ± 4.03</td>
</tr>
<tr>
<td align="left" valign="middle">INF-SEPT LS</td>
<td align="center" valign="middle">-8.83 ± 4.16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV GLS (%)</td>
<td align="center" valign="middle">10.76 ± 2.20</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN3"><p>LA: left atrium; LV: left ventricle; LVEF: left ventricle ejection fraction; LV ESV: Left Ventricular End-Systolic Volume; LV EDV: Left Ventricular End-Diastolic Volume; LV GLS: Left Ventricular Global Longitudinal Strain; ANT-SEPT LS: Anterior-Septal Longitudinal Strain; ANT LS: Anterior Longitudinal Strain; ANT-LAT LS: Anterior-Lateral Longitudinal Strain; INF-LAT LS: Inferior-Lateral Longitudinal Strain; INF LS: Inferior Longitudinal Strain; INF-SEPT LS: Inferior-Septal Longitudinal Strain; E-e’ ratio: Ratio of early transmitral flow velocity (E) to early diastolic tissue velocity (e’) in echocardiography; LVSd: Left Ventricular Septal Diameter; LVDd: Left Ventricular Diastolic Diameter.</p></fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="t4">
<label>Table 4</label>
<caption><title>Mean values of participants with indeterminate form.</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variable</th>
<th align="center" valign="middle">Value</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">5</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Age</td>
<td align="center" valign="middle">72.51 ± 5.19</td>
</tr>
<tr>
<td align="left" valign="middle">Body surface area (sq meter)</td>
<td align="center" valign="middle">1.7826 ± 0.26</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVEF (0/0)</td>
<td align="center" valign="middle">57.80 ± 6.49</td>
</tr>
<tr>
<td align="left" valign="middle">LA volume index (ml sq meter)</td>
<td align="center" valign="middle">32.69 ± 7.29</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV mass (g)</td>
<td align="center" valign="middle">284.6 ± 64.98</td>
</tr>
<tr>
<td align="left" valign="middle">LVSd (mm)</td>
<td align="center" valign="middle">39.93 ± 8.30</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LVDd (mm)</td>
<td align="center" valign="middle">59 ± 5.86</td>
</tr>
<tr>
<td align="left" valign="middle">LV ESV (ml)</td>
<td align="center" valign="middle">72.67 ± 37.58</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV EDV (ml)</td>
<td align="center" valign="middle">173.8 ± 39.57</td>
</tr>
<tr>
<td align="left" valign="middle">E-e&apos; ratio</td>
<td align="center" valign="middle">12.76 ± 3.31</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">ANT-SEPT LS</td>
<td align="center" valign="middle">-17.4 ± 3.65</td>
</tr>
<tr>
<td align="left" valign="middle">ANT LS</td>
<td align="center" valign="middle">-19.4 ± 6.50</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">ANT-LAT LS</td>
<td align="center" valign="middle">-19 ± 5.92</td>
</tr>
<tr>
<td align="left" valign="middle">INF-LAT LS (%)</td>
<td align="center" valign="middle">-16.8 ± 3.89</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">INF LS (%)</td>
<td align="center" valign="middle">-15.6 ± 5.59</td>
</tr>
<tr>
<td align="left" valign="middle">INF-SEPT LS</td>
<td align="center" valign="middle">-15 ± 6.24</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">LV GLS (%)</td>
<td align="center" valign="middle">17.34 ± 3.82</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN4"><p>LA: left atrium; LV: left ventricle; LVEF: left ventricle ejection fraction; LV ESV: Left Ventricular End-Systolic Volume; LV EDV: Left Ventricular End-Diastolic Volume; LV GLS: Left Ventricular Global Longitudinal Strain; ANT-SEPT LS: Anterior-Septal Longitudinal Strain; ANT LS: Anterior Longitudinal Strain; ANT-LAT LS: Anterior-Lateral Longitudinal Strain; INF-LAT LS: Inferior-Lateral Longitudinal Strain; INF LS: Inferior Longitudinal Strain; INF-SEPT LS: Inferior-Septal Longitudinal Strain; E-e’ ratio: Ratio of early transmitral flow velocity (E) to early diastolic tissue velocity (e’) in echocardiography; LVSd: Left Ventricular Septal Diameter; LVDd: Left Ventricular Diastolic Diameter.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>The mean left ventricle ejection fraction LVEF was 33 ± 2.88, and the mean GLS of the left ventricle was −10.76 ± 2.20 in the chronic form as compared to 57.80 ± 6.49 and −17.34 ± 3.82, respectively in the indeterminate group. In relation to left ventricle segmental strain, each segment was evaluated individually in each group. Myocardial deformity analysis by speckle tracking was significantly reduced in all segments of the inferior, inferoseptal and anteroseptal walls in both categories (<xref ref-type="fig" rid="f2">Figure 2</xref>). This finding aligns with literature suggesting that these areas are susceptible to early inflammatory changes and fibrosis in the indeterminate phase of Chagas disease, which can occur before significant left ventricular dysfunction manifests. Previous studies have identified these segmental abnormalities as early indicators of myocardial damage, even in the absence of overt clinical symptoms.<sup><xref ref-type="bibr" rid="B17">17</xref>,<xref ref-type="bibr" rid="B18">18</xref></sup></p>
<fig id="f2">
<label>Figure 2</label>
<caption>
<title>As represented in the bull&apos;s eye, segmental contractility of the left ventricle analyzed by bidimensional strain derived from STE was significantly reduced in the inferior, inferoseptal, and anteroseptal walls, with similar results in both groups. ANT-SEPT: Anterior-Septal; ANT: Anterior; ANT-LAT: Anterior-Lateral; INF-LAT: Inferior-Lateral; INF: Inferior; INF-SEPT: Inferior-Septal</title></caption>
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf02.tif"/>
</fig>
</sec>
</sec>
<sec sec-type="discussion">
<title>Discussion</title>
<p>Chagas disease cardiac involvement presents most commonly in the form of dilated cardiomyopathy as a result of chronic inflammation with subsequent cardiomyocyte loss. The final stage of the disease is characterized by the disruption of muscle fibers and neuronal structures with replacement by fibrotic tissue. This architectural anomaly contributes to electrophysiological dysfunction and is a major factor in the propensity of chagasic individuals to experience ventricular arrhythmias and heart failure,<sup><xref ref-type="bibr" rid="B18">18</xref>,<xref ref-type="bibr" rid="B20">20</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> accounting for considerable morbidity and mortality.<sup><xref ref-type="bibr" rid="B15">15</xref></sup> The degree of ventricular dysfunction also determines the severity of ventricular arrhythmia. One of the main causes of death in this population is SCD, accounting for nearly 55-60% of deaths. Patients with a history of syncope, severe bradyarrhythmia, and cardiac arrest are more likely to develop SCD.<sup><xref ref-type="bibr" rid="B18">18</xref>,<xref ref-type="bibr" rid="B21">21</xref>,<xref ref-type="bibr" rid="B22">22</xref></sup> Clinical features can be divided into three stages: acute, indeterminate, and chronic. Acute Chagas disease typically persists from 8 to 12 weeks. It frequently remains undiagnosed because most patients are asymptomatic or experience only mild and nonspecific symptoms such as fever, tiredness, lymphadenopathy, hepatomegaly, and splenomegaly. Local signs at the infection site may also be noted, like the characteristic chagoma (T. cruzi skin abscess) or the Romaña sign (unilateral conjunctivitis with painless swelling of the eyelids). Other organ systems less frequently involved include the gastrointestinal tract and nervous system. The fulminant disease commonly presents with acute myocarditis, pericardial effusion, and mural thrombosis.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> In the indeterminate phase, patients are asymptomatic and have preserved LVEF. Nearly 20-40% of patients with acute Chagas disease<sup><xref ref-type="bibr" rid="B23">23</xref></sup> develop the chronic disease 20 to 30 years later, either in the form of megaesophagus, megacolon or Chagas Heart disease.<sup><xref ref-type="bibr" rid="B24">24</xref></sup> Cardiac involvement is marked by significant arrhythmias (both supraventricular or ventricular) and ventricular aneurysms.<sup><xref ref-type="bibr" rid="B25">25</xref></sup> Damage to the electrical conduction system is also a prevalent cause of atrioventricular block,<sup><xref ref-type="bibr" rid="B15">15</xref></sup> with right bundle branch block (RBBB) as the most common intraventricular conduction abnormality and often one of the first manifestations of the disease. The combination of RBBB and left anterior fascicular block is strongly suggestive of Chagas disease<sup><xref ref-type="bibr" rid="B18">18</xref></sup> in high-risk groups. Pulmonary and systemic thromboembolism formation,<sup><xref ref-type="bibr" rid="B26">26</xref></sup> myocardial scarring and wall motion abnormalities, most commonly in the apical and inferolateral walls, are also reported. Cardiac manifestations make up a significant part of Chagas disease morbidity and mortality, but clinical deterioration can have an insidious course, as seen in the indeterminate form. We intend to compare the progression of left ventricular function through multiple echocardiographic parameters in indeterminate and chronic forms of Chagas disease through a case series. In doing so, we suggested the possibility of using GLS as an incremental value to the ejection fraction of the left ventricle in the early identification of cardiac changes. In the indeterminate group, these segmental contractility alterations are particularly noteworthy. Early myocardial damage characterized by inflammation and fibrosis, often localized in the inferior, inferoseptal, and anteroseptal walls, has been documented in patients with indeterminate Chagas disease. This supports our observation of contractility changes in these segments, underscoring the need for vigilant cardiac monitoring even in asymptomatic patients. The pathophysiological basis for these changes involves an ongoing inflammatory response, with subsequent fibrosis, which disrupts normal myocardial function, particularly in these vulnerable regions.<sup><xref ref-type="bibr" rid="B15">15</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> Concurrently, a literature review of the topic was also conducted. The analysis of left ventricular myocardial changes in Chagas cardiomyopathy using speckle tracking was first studied across the spectrum of ejection fractions (from preserved to reduced) by Lima et al.<sup><xref ref-type="bibr" rid="B27">27</xref></sup> Speckle tracking is an echocardiographic tool that allows automated quantitative frame-by-frame tracking of interactions between acoustic changes and regional myocardial changes.<sup><xref ref-type="bibr" rid="B27">27</xref>,<xref ref-type="bibr" rid="B28">28</xref></sup> The study showed a decreased strain in the inferior and posterior heart walls with a paradoxical increase in septal and anterior segments across the evolution of Chagas cardiomyopathy. It also demonstrated reduced longitudinal velocities in the indeterminate form.<sup><xref ref-type="bibr" rid="B27">27</xref></sup> Another cross-sectional study was able to demonstrate an early abnormal change in regional longitudinal strain in patients with indeterminate form localized to the inferior, septal inferior and inferolateral segments. When compared with cardiac magnetic resonance imaging, these changes occurred before cardiac fibrosis.<sup><xref ref-type="bibr" rid="B29">29</xref></sup> The prognostic value of biomarkers and strain parameters has been prospectively studied more recently in the same cohort that demonstrated an independent association of LV GLS, left ventricular torsion and brain natriuretic peptide (BNP) levels with a composite outcome consisting of mortality, hospital admission, heart transplant or device implantation in patients with chronic Chagas disease.<sup><xref ref-type="bibr" rid="B30">30</xref></sup> In our review, we have included the study data on STE in Chagas disease currently present in literature (<xref ref-type="table" rid="t5">Table 5</xref>). The general concept and summary of this case series and literature review are presented in the <xref ref-type="fig" rid="f3">central figure</xref>.</p>
<table-wrap id="t5">
<label>Table 5</label>
<caption><title>Data on STE in Chagas disease currently present in literature</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="25%">
<col/>
<col/>
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Author</th>
<th align="center" valign="middle">Type of Study</th>
<th align="center" valign="middle">Participants</th>
<th align="left" valign="middle">Parameters</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">Garcia-Alvaraez et al. (2011)<sup><xref ref-type="bibr" rid="B31">31</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">98</td>
<td align="left" valign="middle">GLS, radial and circumferential strain</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Barbosa et al. (2014)<sup><xref ref-type="bibr" rid="B32">32</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">78</td>
<td align="left" valign="middle">GLS, radial and circumferential strain</td>
</tr>
<tr>
<td align="left" valign="middle">Gomes et al. (2016)<sup><xref ref-type="bibr" rid="B33">33</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">126</td>
<td align="left" valign="middle">GLS, radial and circumferential strain</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Lima et al. (2016)<sup><xref ref-type="bibr" rid="B27">27</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">131</td>
<td align="left" valign="middle">GLS, twist/torsion and rotational strain</td>
</tr>
<tr>
<td align="left" valign="middle">Lima et al. (2017)<sup><xref ref-type="bibr" rid="B34">34</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">42</td>
<td align="left" valign="middle">GLS, twist/torsion and rotational strain</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Santos Jr. et al. (2019)<sup><xref ref-type="bibr" rid="B35">35</xref></sup></td>
<td align="center" valign="middle">Prospective cohort</td>
<td align="center" valign="middle">122</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr>
<td align="left" valign="middle">Echeverría et al. (2020)<sup><xref ref-type="bibr" rid="B36">36</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">273</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Cianciulli et al. (2021)<sup><xref ref-type="bibr" rid="B28">28</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">90</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr>
<td align="left" valign="middle">Romano et al. (2020)<sup><xref ref-type="bibr" rid="B29">29</xref></sup></td>
<td align="center" valign="middle">Cross-sectional</td>
<td align="center" valign="middle">69</td>
<td align="left" valign="middle">GLS, radial and circumferential strain</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Echeverría et al. (2022)<sup><xref ref-type="bibr" rid="B17">17</xref></sup></td>
<td align="center" valign="middle">Prospective cohort</td>
<td align="center" valign="middle">177</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr>
<td align="left" valign="middle">Win et al. (2022)<sup><xref ref-type="bibr" rid="B15">15</xref></sup></td>
<td align="center" valign="middle">Prospective cohort</td>
<td align="center" valign="middle">139</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Hotta et al. (2022)<sup><xref ref-type="bibr" rid="B23">23</xref></sup></td>
<td align="center" valign="middle">Prospective cohort</td>
<td align="center" valign="middle">72</td>
<td align="left" valign="middle">GLS</td>
</tr>
<tr>
<td align="left" valign="middle">Mendes et al. (2023)<sup><xref ref-type="bibr" rid="B30">30</xref></sup></td>
<td align="center" valign="middle">Prospective cohort</td>
<td align="center" valign="middle">361</td>
<td align="left" valign="middle">GLS</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN5"><p>GLS: Global longitudinal strain.</p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec sec-type="conclusions">
<title>Conclusion</title>
<p>Our study highlights the importance of early detection and management of myocardial involvement in Chagas disease. The addition of GLS analysis to conventional echocardiography yields a potential incremental value at the detection of subclinical myocardial changes before a significant reduction in left ventricle ejection fraction. The segmental contractility alterations observed in the indeterminate group emphasize the significance of recognizing early myocardial damage. Targeted imaging and timely interventions are crucial to managing these patients effectively and preventing progression to symptomatic heart disease. When compared to patients with the chronic variant of Chagas disease, individual segmental analysis in the indeterminate form may allow early recognition of patients at risk for progression to clinical cardiac dysfunction as suggested by this case series and systematic literature review in line with currently available data. Our findings are consistent with existing literature that highlights the subclinical myocardial involvement in the indeterminate phase of Chagas disease, which necessitates proactive cardiac evaluation and management strategies to mitigate long-term complications. However, the clinical impact and significance of these newer techniques remain unknown.</p>
</sec>
</body>
<back>
<fn-group>
<fn fn-type="financial-disclosure" id="fn1"><label>Sources of Funding</label><p>There were no external funding sources for this study.</p></fn>
<fn fn-type="other" id="fn2"><label>Study Association</label><p>This study is not associated with any thesis or dissertation work.</p></fn>
<fn fn-type="other" id="fn3"><label>Ethics Approval and Consent to Participate</label><p>This study was approved by the Ethics Committee of the Comitê de Ética da Central de Diagnóstico e Pesquisa Clínica under the protocol number 01.2023/579831. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study.</p></fn>
</fn-group>
<ref-list>
<title>References</title>
<ref id="B1">
<label>1</label>
<element-citation publication-type="book">
<person-group person-group-type="author">
<collab>World Health Organization</collab>
</person-group>
<source>Global Burden of Disease Estimates: 2004 Update</source>
<publisher-loc>Geneva</publisher-loc>
<publisher-name>WHO</publisher-name>
<year>2008</year>
</element-citation>
<mixed-citation>World Health Organization. Global Burden of Disease Estimates: 2004 Update. Geneva: WHO; 2008.</mixed-citation>
</ref>
<ref id="B2">
<label>2</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fuentes-Vicente</surname><given-names>JA</given-names></name>
<name><surname>Gutiérrez-Cabrera</surname><given-names>AE</given-names></name>
<name><surname>Flores-Villegas</surname><given-names>AL</given-names></name>
<name><surname>Lowenberger</surname><given-names>C</given-names></name>
<name><surname>Benelli</surname><given-names>G</given-names></name>
<name><surname>Salazar-Schettino</surname><given-names>PM</given-names></name>
<etal/>
</person-group>
<article-title>What Makes an Effective Chagas Disease Vector? Factors Underlying Trypanosoma Cruzi-triatomine Interactions</article-title>
<source>Acta Trop</source>
<year>2018</year>
<volume>183</volume>
<fpage>23</fpage>
<lpage>31</lpage>
<pub-id pub-id-type="doi">10.1016/j.actatropica.2018.04.008</pub-id>
</element-citation>
<mixed-citation>Fuentes-Vicente JA, Gutiérrez-Cabrera AE, Flores-Villegas AL, Lowenberger C, Benelli G, Salazar-Schettino PM, et al. What Makes an Effective Chagas Disease Vector? Factors Underlying Trypanosoma Cruzi-triatomine Interactions. Acta Trop. 2018;183:23-31. doi: 10.1016/j.actatropica.2018.04.008.</mixed-citation>
</ref>
<ref id="B3">
<label>3</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Chagas</surname><given-names>C</given-names></name>
</person-group>
<article-title>Nova Tripanozomiaze Humana: Estudos sobre a Morfolojia e o Ciclo Evolutivo do Schizotrypanum Cruzi n. gen., n. sp., Ajente Etiolojico de Nova Entidade Morbida do Homem</article-title>
<source>Mem Inst Oswaldo Cruz</source>
<year>1909</year>
<volume>1</volume>
<fpage>159</fpage>
<lpage>218</lpage>
<pub-id pub-id-type="doi">10.1590/S0074-02761909000200008</pub-id>
</element-citation>
<mixed-citation>Chagas C. Nova Tripanozomiaze Humana: Estudos sobre a Morfolojia e o Ciclo Evolutivo do Schizotrypanum Cruzi n. gen., n. sp., Ajente Etiolojico de Nova Entidade Morbida do Homem. Mem Inst Oswaldo Cruz. 1909;1:159-218. doi: 10.1590/S0074-02761909000200008.</mixed-citation>
</ref>
<ref id="B4">
<label>4</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Dias</surname><given-names>JC</given-names></name>
<name><surname>Silveira</surname><given-names>AC</given-names></name>
<name><surname>Schofield</surname><given-names>CJ</given-names></name>
</person-group>
<article-title>The Impact of Chagas Disease Control in Latin America: A Review</article-title>
<source>Mem Inst Oswaldo Cruz</source>
<year>2002</year>
<volume>97</volume>
<issue>5</issue>
<fpage>603</fpage>
<lpage>612</lpage>
<pub-id pub-id-type="doi">10.1590/s0074-02762002000500002</pub-id>
</element-citation>
<mixed-citation>Dias JC, Silveira AC, Schofield CJ. The Impact of Chagas Disease Control in Latin America: A Review. Mem Inst Oswaldo Cruz. 2002;97(5):603-12. doi: 10.1590/s0074-02762002000500002.</mixed-citation>
</ref>
<ref id="B5">
<label>5</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Gómez-Ochoa</surname><given-names>SA</given-names></name>
<name><surname>Rojas</surname><given-names>LZ</given-names></name>
<name><surname>Echeverría</surname><given-names>LE</given-names></name>
<name><surname>Muka</surname><given-names>T</given-names></name>
<name><surname>Franco</surname><given-names>OH</given-names></name>
</person-group>
<article-title>Global, Regional, and National Trends of Chagas Disease from 1990 to 2019: Comprehensive Analysis of the Global Burden of Disease Study</article-title>
<source>Glob Heart</source>
<year>2022</year>
<volume>17</volume>
<issue>1</issue>
<fpage>59</fpage>
<lpage>59</lpage>
<pub-id pub-id-type="doi">10.5334/gh.1150</pub-id>
</element-citation>
<mixed-citation>Gómez-Ochoa SA, Rojas LZ, Echeverría LE, Muka T, Franco OH. Global, Regional, and National Trends of Chagas Disease from 1990 to 2019: Comprehensive Analysis of the Global Burden of Disease Study. Glob Heart. 2022;17(1):59. doi: 10.5334/gh.1150.</mixed-citation>
</ref>
<ref id="B6">
<label>6</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Gascon</surname><given-names>J</given-names></name>
<name><surname>Bern</surname><given-names>C</given-names></name>
<name><surname>Pinazo</surname><given-names>MJ</given-names></name>
</person-group>
<article-title>Chagas Disease in Spain, the United States and Other Non-endemic Countries</article-title>
<source>Acta Trop</source>
<year>2010</year>
<volume>115</volume>
<issue>1-2</issue>
<fpage>22</fpage>
<lpage>27</lpage>
<pub-id pub-id-type="doi">10.1016/j.actatropica.2009.07.019</pub-id>
</element-citation>
<mixed-citation>Gascon J, Bern C, Pinazo MJ. Chagas Disease in Spain, the United States and Other Non-endemic Countries. Acta Trop. 2010;115(1-2):22-7. doi: 10.1016/j.actatropica.2009.07.019.</mixed-citation>
</ref>
<ref id="B7">
<label>7</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Dorn</surname><given-names>PL</given-names></name>
<name><surname>Perniciaro</surname><given-names>L</given-names></name>
<name><surname>Yabsley</surname><given-names>MJ</given-names></name>
<name><surname>Roellig</surname><given-names>DM</given-names></name>
<name><surname>Balsamo</surname><given-names>G</given-names></name>
<name><surname>Diaz</surname><given-names>J</given-names></name>
<etal/>
</person-group>
<article-title>Autochthonous Transmission of Trypanosoma Cruzi, Louisiana</article-title>
<source>Emerg Infect Dis</source>
<year>2007</year>
<volume>13</volume>
<issue>4</issue>
<fpage>605</fpage>
<lpage>607</lpage>
<pub-id pub-id-type="doi">10.3201/eid1304.061002</pub-id>
</element-citation>
<mixed-citation>Dorn PL, Perniciaro L, Yabsley MJ, Roellig DM, Balsamo G, Diaz J, et al. Autochthonous Transmission of Trypanosoma Cruzi, Louisiana. Emerg Infect Dis. 2007;13(4):605-7. doi: 10.3201/eid1304.061002.</mixed-citation>
</ref>
<ref id="B8">
<label>8</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Cantey</surname><given-names>PT</given-names></name>
<name><surname>Stramer</surname><given-names>SL</given-names></name>
<name><surname>Townsend</surname><given-names>RL</given-names></name>
<name><surname>Kamel</surname><given-names>H</given-names></name>
<name><surname>Ofafa</surname><given-names>K</given-names></name>
<name><surname>Todd</surname><given-names>CW</given-names></name>
<etal/>
</person-group>
<article-title>The United States Trypanosoma Cruzi Infection Study: Evidence for Vector-borne Transmission of the Parasite that Causes Chagas Disease Among United States Blood Donors</article-title>
<source>Transfusion</source>
<year>2012</year>
<volume>52</volume>
<issue>9</issue>
<fpage>1922</fpage>
<lpage>1930</lpage>
<pub-id pub-id-type="doi">10.1111/j.1537-2995.2012.03581.x</pub-id>
</element-citation>
<mixed-citation>Cantey PT, Stramer SL, Townsend RL, Kamel H, Ofafa K, Todd CW, et al. The United States Trypanosoma Cruzi Infection Study: Evidence for Vector-borne Transmission of the Parasite that Causes Chagas Disease Among United States Blood Donors. Transfusion. 2012;52(9):1922-30. doi: 10.1111/j.1537-2995.2012.03581.x.</mixed-citation>
</ref>
<ref id="B9">
<label>9</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Chin-Hong</surname><given-names>PV</given-names></name>
<name><surname>Schwartz</surname><given-names>BS</given-names></name>
<name><surname>Bern</surname><given-names>C</given-names></name>
<name><surname>Montgomery</surname><given-names>SP</given-names></name>
<name><surname>Kontak</surname><given-names>S</given-names></name>
<name><surname>Kubak</surname><given-names>B</given-names></name>
<etal/>
</person-group>
<article-title>Screening and Treatment of Chagas Disease in Organ Transplant Recipients in the United States: Recommendations from the Chagas in Transplant Working Group</article-title>
<source>Am J Transplant</source>
<year>2011</year>
<volume>11</volume>
<issue>4</issue>
<fpage>672</fpage>
<lpage>680</lpage>
<pub-id pub-id-type="doi">10.1111/j.1600-6143.2011.03444.x</pub-id>
</element-citation>
<mixed-citation>Chin-Hong PV, Schwartz BS, Bern C, Montgomery SP, Kontak S, Kubak B, et al. Screening and Treatment of Chagas Disease in Organ Transplant Recipients in the United States: Recommendations from the Chagas in Transplant Working Group. Am J Transplant. 2011;11(4):672-80. doi: 10.1111/j.1600-6143.2011.03444.x.</mixed-citation>
</ref>
<ref id="B10">
<label>10</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Schijman</surname><given-names>AG</given-names></name>
<name><surname>Vigliano</surname><given-names>C</given-names></name>
<name><surname>Burgos</surname><given-names>J</given-names></name>
<name><surname>Favaloro</surname><given-names>R</given-names></name>
<name><surname>Perrone</surname><given-names>S</given-names></name>
<name><surname>Laguens</surname><given-names>R</given-names></name>
<etal/>
</person-group>
<article-title>Early Diagnosis of Recurrence of Trypanosoma Cruzi Infection by Polymerase Chain Reaction after Heart Transplantation of a Chronic Chagas’ Heart Disease Patient</article-title>
<source>J Heart Lung Transplant</source>
<year>2000</year>
<volume>19</volume>
<issue>11</issue>
<fpage>1114</fpage>
<lpage>1117</lpage>
<pub-id pub-id-type="doi">10.1016/s1053-2498(00)00168-6</pub-id>
</element-citation>
<mixed-citation>Schijman AG, Vigliano C, Burgos J, Favaloro R, Perrone S, Laguens R, et al. Early Diagnosis of Recurrence of Trypanosoma Cruzi Infection by Polymerase Chain Reaction after Heart Transplantation of a Chronic Chagas’ Heart Disease Patient. J Heart Lung Transplant. 2000;19(11):1114-7. doi: 10.1016/s1053-2498(00)00168-6.</mixed-citation>
</ref>
<ref id="B11">
<label>11</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Gomes</surname><given-names>ML</given-names></name>
<name><surname>Galvao</surname><given-names>LM</given-names></name>
<name><surname>Macedo</surname><given-names>AM</given-names></name>
<name><surname>Pena</surname><given-names>SD</given-names></name>
<name><surname>Chiari</surname><given-names>E</given-names></name>
</person-group>
<article-title>Chagas’ Disease Diagnosis: Comparative Analysis of Parasitologic, Molecular, and Serologic Methods</article-title>
<source>Am J Trop Med Hyg</source>
<year>1999</year>
<volume>60</volume>
<issue>2</issue>
<fpage>205</fpage>
<lpage>210</lpage>
<pub-id pub-id-type="doi">10.4269/ajtmh.1999.60.205</pub-id>
</element-citation>
<mixed-citation>Gomes ML, Galvao LM, Macedo AM, Pena SD, Chiari E. Chagas’ Disease Diagnosis: Comparative Analysis of Parasitologic, Molecular, and Serologic Methods. Am J Trop Med Hyg. 1999;60(2):205-10. doi: 10.4269/ajtmh.1999.60.205.</mixed-citation>
</ref>
<ref id="B12">
<label>12</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bern</surname><given-names>C</given-names></name>
<name><surname>Montgomery</surname><given-names>SP</given-names></name>
<name><surname>Herwaldt</surname><given-names>BL</given-names></name>
<name><surname>Rassi</surname><given-names>A</given-names><suffix>Jr</suffix></name>
<name><surname>Marin-Neto</surname><given-names>JA</given-names></name>
<name><surname>Dantas</surname><given-names>RO</given-names></name>
<etal/>
</person-group>
<article-title>Evaluation and Treatment of Chagas Disease in the United States: A Systematic Review</article-title>
<source>JAMA</source>
<year>2007</year>
<volume>298</volume>
<issue>18</issue>
<fpage>2171</fpage>
<lpage>2181</lpage>
<pub-id pub-id-type="doi">10.1001/jama.298.18.2171</pub-id>
</element-citation>
<mixed-citation>Bern C, Montgomery SP, Herwaldt BL, Rassi A Jr, Marin-Neto JA, Dantas RO, et al. Evaluation and Treatment of Chagas Disease in the United States: A Systematic Review. JAMA. 2007;298(18):2171-81. doi: 10.1001/jama.298.18.2171.</mixed-citation>
</ref>
<ref id="B13">
<label>13</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<collab>Brasil. Ministério da Saúde</collab>
</person-group>
<article-title>Secretaria de Vigilância em Saúde. Brazilian Consensus on Chagas Disease</article-title>
<source>Rev Soc Bras Med Trop</source>
<year>2005</year>
<volume>38</volume>
<supplement>Suppl 3</supplement>
<fpage>7</fpage>
<lpage>29</lpage>
</element-citation>
<mixed-citation>Brasil. Ministério da Saúde. Secretaria de Vigilância em Saúde. Brazilian Consensus on Chagas Disease. Rev Soc Bras Med Trop. 2005;38(Suppl 3):7-29.</mixed-citation>
</ref>
<ref id="B14">
<label>14</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kang</surname><given-names>Y</given-names></name>
<name><surname>Xu</surname><given-names>X</given-names></name>
<name><surname>Cheng</surname><given-names>L</given-names></name>
<name><surname>Li</surname><given-names>L</given-names></name>
<name><surname>Sun</surname><given-names>M</given-names></name>
<name><surname>Chen</surname><given-names>H</given-names></name>
<etal/>
</person-group>
<article-title>Two-dimensional Speckle Tracking Echocardiography Combined with High-sensitive Cardiac Troponin T in Early Detection and Prediction of Cardiotoxicity During Epirubicine-based Chemotherapy</article-title>
<source>Eur J Heart Fail</source>
<year>2014</year>
<volume>16</volume>
<issue>3</issue>
<fpage>300</fpage>
<lpage>308</lpage>
<pub-id pub-id-type="doi">10.1002/ejhf.8</pub-id>
</element-citation>
<mixed-citation>Kang Y, Xu X, Cheng L, Li L, Sun M, Chen H, et al. Two-dimensional Speckle Tracking Echocardiography Combined with High-sensitive Cardiac Troponin T in Early Detection and Prediction of Cardiotoxicity During Epirubicine-based Chemotherapy. Eur J Heart Fail. 2014;16(3):300-8. doi: 10.1002/ejhf.8.</mixed-citation>
</ref>
<ref id="B15">
<label>15</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Win</surname><given-names>S</given-names></name>
<name><surname>Miranda-Schaeubinger</surname><given-names>M</given-names></name>
<name><surname>Saucedo</surname><given-names>RGD</given-names></name>
<name><surname>Jimenez</surname><given-names>PC</given-names></name>
<name><surname>Flores</surname><given-names>J</given-names></name>
<name><surname>Mercado-Saavedra</surname><given-names>B</given-names></name>
<etal/>
</person-group>
<article-title>Early Identification of Patients with Chagas Disease at Risk of Developing Cardiomyopathy Using 2-D Speckle Tracking Strain: Win, Miranda Prediction of Chagas Cardiomyopathy</article-title>
<source>Int J Cardiol Heart Vasc</source>
<year>2022</year>
<volume>41</volume>
<fpage>101060</fpage>
<lpage>101060</lpage>
<pub-id pub-id-type="doi">10.1016/j.ijcha.2022.101060</pub-id>
</element-citation>
<mixed-citation>Win S, Miranda-Schaeubinger M, Saucedo RGD, Jimenez PC, Flores J, Mercado-Saavedra B, et al. Early Identification of Patients with Chagas Disease at Risk of Developing Cardiomyopathy Using 2-D Speckle Tracking Strain: Win, Miranda Prediction of Chagas Cardiomyopathy. Int J Cardiol Heart Vasc. 2022;41:101060. doi: 10.1016/j.ijcha.2022.101060.</mixed-citation>
</ref>
<ref id="B16">
<label>16</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Collier</surname><given-names>P</given-names></name>
<name><surname>Phelan</surname><given-names>D</given-names></name>
<name><surname>Klein</surname><given-names>A</given-names></name>
</person-group>
<article-title>A Test in Context: Myocardial Strain Measured by Speckle-tracking Echocardiography</article-title>
<source>J Am Coll Cardiol</source>
<year>2017</year>
<volume>69</volume>
<issue>8</issue>
<fpage>1043</fpage>
<lpage>1056</lpage>
<pub-id pub-id-type="doi">10.1016/j.jacc.2016.12.012</pub-id>
</element-citation>
<mixed-citation>Collier P, Phelan D, Klein A. A Test in Context: Myocardial Strain Measured by Speckle-tracking Echocardiography. J Am Coll Cardiol. 2017;69(8):1043-56. doi: 10.1016/j.jacc.2016.12.012.</mixed-citation>
</ref>
<ref id="B17">
<label>17</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Echeverría</surname><given-names>LE</given-names></name>
<name><surname>Rojas</surname><given-names>LZ</given-names></name>
<name><surname>Rueda-Ochoa</surname><given-names>OL</given-names></name>
<name><surname>Gómez-Ochoa</surname><given-names>SA</given-names></name>
<name><surname>Mayer</surname><given-names>MA</given-names></name>
<name><surname>Becerra-Motta</surname><given-names>LP</given-names></name>
<etal/>
</person-group>
<article-title>Longitudinal Strain by Speckle Tracking and Echocardiographic Parameters as Predictors of Adverse Cardiovascular Outcomes in Chronic Chagas Cardiomyopathy</article-title>
<source>Int J Cardiovasc Imaging</source>
<year>2022</year>
<volume>38</volume>
<issue>6</issue>
<fpage>1245</fpage>
<lpage>1255</lpage>
<pub-id pub-id-type="doi">10.1007/s10554-021-02508-5</pub-id>
</element-citation>
<mixed-citation>Echeverría LE, Rojas LZ, Rueda-Ochoa OL, Gómez-Ochoa SA, Mayer MA, Becerra-Motta LP, et al. Longitudinal Strain by Speckle Tracking and Echocardiographic Parameters as Predictors of Adverse Cardiovascular Outcomes in Chronic Chagas Cardiomyopathy. Int J Cardiovasc Imaging. 2022;38(6):1245-55. doi: 10.1007/s10554-021-02508-5.</mixed-citation>
</ref>
<ref id="B18">
<label>18</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Nunes</surname><given-names>MCP</given-names></name>
<name><surname>Beaton</surname><given-names>A</given-names></name>
<name><surname>Acquatella</surname><given-names>H</given-names></name>
<name><surname>Bern</surname><given-names>C</given-names></name>
<name><surname>Bolger</surname><given-names>AF</given-names></name>
<name><surname>Echeverría</surname><given-names>LE</given-names></name>
<etal/>
</person-group>
<article-title>Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement from the American Heart Association</article-title>
<source>Circulation</source>
<year>2018</year>
<volume>138</volume>
<issue>12</issue>
<fpage>169</fpage>
<lpage>209</lpage>
<pub-id pub-id-type="doi">10.1161/CIR.0000000000000599</pub-id>
</element-citation>
<mixed-citation>Nunes MCP, Beaton A, Acquatella H, Bern C, Bolger AF, Echeverría LE, et al. Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement from the American Heart Association. Circulation. 2018;138(12):169-209. doi: 10.1161/CIR.0000000000000599.</mixed-citation>
</ref>
<ref id="B19">
<label>19</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lang</surname><given-names>RM</given-names></name>
<name><surname>Badano</surname><given-names>LP</given-names></name>
<name><surname>Mor-Avi</surname><given-names>V</given-names></name>
<name><surname>Afilalo</surname><given-names>J</given-names></name>
<name><surname>Armstrong</surname><given-names>A</given-names></name>
<name><surname>Ernande</surname><given-names>L</given-names></name>
<etal/>
</person-group>
<article-title>Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging</article-title>
<source>J Am Soc Echocardiogr</source>
<year>2015</year>
<volume>28</volume>
<issue>1</issue>
<fpage>1..e14</fpage>
<lpage>39.e14</lpage>
<pub-id pub-id-type="doi">10.1016/j.echo.2014.10.003</pub-id>
</element-citation>
<mixed-citation>Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, et al. Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28(1):1-39.e14. doi: 10.1016/j.echo.2014.10.003.</mixed-citation>
</ref>
<ref id="B20">
<label>20</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rocha</surname><given-names>MO</given-names></name>
<name><surname>Ribeiro</surname><given-names>ALP</given-names></name>
<name><surname>Teixeira</surname><given-names>MM</given-names></name>
</person-group>
<article-title>Clinical Management of Chronic Chagas Cardiomyopathy</article-title>
<source>Front Biosci</source>
<year>2003</year>
<volume>8</volume>
<fpage>e44</fpage>
<lpage>e54</lpage>
<pub-id pub-id-type="doi">10.2741/926</pub-id>
</element-citation>
<mixed-citation>Rocha MO, Ribeiro ALP, Teixeira MM. Clinical Management of Chronic Chagas Cardiomyopathy. Front Biosci. 2003;8:e44-54. doi: 10.2741/926.</mixed-citation>
</ref>
<ref id="B21">
<label>21</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Andrade</surname><given-names>JP</given-names></name>
<name><surname>Marin-Neto</surname><given-names>JA</given-names></name>
<name><surname>Paola</surname><given-names>AA</given-names></name>
<name><surname>Vilas-Boas</surname><given-names>F</given-names></name>
<name><surname>Oliveira</surname><given-names>GM</given-names></name>
<name><surname>Bacal</surname><given-names>F</given-names></name>
<etal/>
</person-group>
<article-title>I Latin American Guidelines for the Diagnosis and Treatment of Chagas’ Heart Disease: Executive Summary</article-title>
<source>Arq Bras Cardiol</source>
<year>2011</year>
<volume>96</volume>
<issue>6</issue>
<fpage>434</fpage>
<lpage>442</lpage>
<pub-id pub-id-type="doi">10.1590/s0066-782x2011000600002</pub-id>
</element-citation>
<mixed-citation>Andrade JP, Marin-Neto JA, Paola AA, Vilas-Boas F, Oliveira GM, Bacal F, et al. I Latin American Guidelines for the Diagnosis and Treatment of Chagas’ Heart Disease: Executive Summary. Arq Bras Cardiol. 2011;96(6):434-42. doi: 10.1590/s0066-782x2011000600002.</mixed-citation>
</ref>
<ref id="B22">
<label>22</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rassi</surname><given-names>A</given-names><suffix>Jr</suffix></name>
<name><surname>Rassi</surname><given-names>SG</given-names></name>
<name><surname>Rassi</surname><given-names>A</given-names></name>
</person-group>
<article-title>Sudden Death in Chagas’ Disease</article-title>
<source>Arq Bras Cardiol</source>
<year>2001</year>
<volume>76</volume>
<issue>1</issue>
<fpage>75</fpage>
<lpage>96</lpage>
<pub-id pub-id-type="doi">10.1590/s0066-782x2001000100008</pub-id>
</element-citation>
<mixed-citation>Rassi A Jr, Rassi SG, Rassi A. Sudden Death in Chagas’ Disease. Arq Bras Cardiol. 2001;76(1):75-96. doi: 10.1590/s0066-782x2001000100008.</mixed-citation>
</ref>
<ref id="B23">
<label>23</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Hotta</surname><given-names>VT</given-names></name>
<name><surname>Abduch</surname><given-names>MCD</given-names></name>
<name><surname>Vieira</surname><given-names>MLC</given-names></name>
<name><surname>Vilela</surname><given-names>AA</given-names></name>
<name><surname>Bocchi</surname><given-names>EA</given-names></name>
</person-group>
<article-title>Three and Two-dimensional Cardiac Mechanics by Speckle Tracking are Predictors of Outcomes in Chagas Heart Disease</article-title>
<source>Sci Rep</source>
<year>2022</year>
<volume>12</volume>
<issue>1</issue>
<fpage>12237</fpage>
<lpage>12237</lpage>
<pub-id pub-id-type="doi">10.1038/s41598-022-16379-w</pub-id>
</element-citation>
<mixed-citation>Hotta VT, Abduch MCD, Vieira MLC, Vilela AA, Bocchi EA. Three and Two-dimensional Cardiac Mechanics by Speckle Tracking are Predictors of Outcomes in Chagas Heart Disease. Sci Rep. 2022;12(1):12237. doi: 10.1038/s41598-022-16379-w.</mixed-citation>
</ref>
<ref id="B24">
<label>24</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rassi</surname><given-names>A</given-names><suffix>Jr</suffix></name>
<name><surname>Rassi</surname><given-names>A</given-names></name>
<name><surname>Little</surname><given-names>WC</given-names></name>
</person-group>
<article-title>Chagas’ Heart Disease</article-title>
<source>Clin Cardiol</source>
<year>2000</year>
<volume>23</volume>
<issue>12</issue>
<fpage>883</fpage>
<lpage>889</lpage>
<pub-id pub-id-type="doi">10.1002/clc.4960231205</pub-id>
</element-citation>
<mixed-citation>Rassi A Jr, Rassi A, Little WC. Chagas’ Heart Disease. Clin Cardiol. 2000;23(12):883-9. doi: 10.1002/clc.4960231205.</mixed-citation>
</ref>
<ref id="B25">
<label>25</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Ribeiro</surname><given-names>FFF</given-names></name>
<name><surname>Moreira</surname><given-names>HT</given-names></name>
<name><surname>Barros-Filho</surname><given-names>ACL</given-names></name>
<name><surname>Tanaka</surname><given-names>DM</given-names></name>
<name><surname>Fabricio</surname><given-names>CG</given-names></name>
<name><surname>Oliveira</surname><given-names>LFL</given-names></name>
<etal/>
</person-group>
<article-title>Prospective Analysis of Myocardial Strain Through the Evolution of Chagas Disease in the Hamster Animal Model</article-title>
<source>Int J Cardiovasc Imaging</source>
<year>2022</year>
<volume>38</volume>
<issue>1</issue>
<fpage>117</fpage>
<lpage>129</lpage>
<pub-id pub-id-type="doi">10.1007/s10554-021-02379-w</pub-id>
</element-citation>
<mixed-citation>Ribeiro FFF, Moreira HT, Barros-Filho ACL, Tanaka DM, Fabricio CG, Oliveira LFL, et al. Prospective Analysis of Myocardial Strain Through the Evolution of Chagas Disease in the Hamster Animal Model. Int J Cardiovasc Imaging. 2022;38(1):117-29. doi: 10.1007/s10554-021-02379-w.</mixed-citation>
</ref>
<ref id="B26">
<label>26</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Choudhuri</surname><given-names>S</given-names></name>
<name><surname>Garg</surname><given-names>NJ</given-names></name>
</person-group>
<article-title>Platelets, Macrophages, and Thromboinflammation in Chagas Disease</article-title>
<source>J Inflamm Res</source>
<year>2022</year>
<volume>15</volume>
<fpage>5689</fpage>
<lpage>5706</lpage>
<pub-id pub-id-type="doi">10.2147/JIR.S380896</pub-id>
</element-citation>
<mixed-citation>Choudhuri S, Garg NJ. Platelets, Macrophages, and Thromboinflammation in Chagas Disease. J Inflamm Res. 2022;15:5689-706. doi: 10.2147/JIR.S380896.</mixed-citation>
</ref>
<ref id="B27">
<label>27</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lima</surname><given-names>MS</given-names></name>
<name><surname>Villarraga</surname><given-names>HR</given-names></name>
<name><surname>Abduch</surname><given-names>MC</given-names></name>
<name><surname>Lima</surname><given-names>MF</given-names></name>
<name><surname>Cruz</surname><given-names>CB</given-names></name>
<name><surname>Bittencourt</surname><given-names>MS</given-names></name>
<etal/>
</person-group>
<article-title>Comprehensive Left Ventricular Mechanics Analysis by Speckle Tracking Echocardiography in Chagas Disease</article-title>
<source>Cardiovasc Ultrasound</source>
<year>2016</year>
<volume>14</volume>
<issue>1</issue>
<fpage>20</fpage>
<lpage>20</lpage>
<pub-id pub-id-type="doi">10.1186/s12947-016-0062-7</pub-id>
</element-citation>
<mixed-citation>Lima MS, Villarraga HR, Abduch MC, Lima MF, Cruz CB, Bittencourt MS, et al. Comprehensive Left Ventricular Mechanics Analysis by Speckle Tracking Echocardiography in Chagas Disease. Cardiovasc Ultrasound. 2016;14(1):20. doi: 10.1186/s12947-016-0062-7.</mixed-citation>
</ref>
<ref id="B28">
<label>28</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Cianciulli</surname><given-names>TF</given-names></name>
<name><surname>Albarracín</surname><given-names>GA</given-names></name>
<name><surname>Llobera</surname><given-names>MN</given-names></name>
<name><surname>Prado</surname><given-names>NG</given-names></name>
<name><surname>Saccheri</surname><given-names>MC</given-names></name>
<name><surname>Vásquez</surname><given-names>YMH</given-names></name>
<etal/>
</person-group>
<article-title>Speckle Tracking Echocardiography in the Indeterminate Form of Chagas Disease</article-title>
<source>Echocardiography</source>
<year>2021</year>
<volume>38</volume>
<issue>1</issue>
<fpage>39</fpage>
<lpage>46</lpage>
<pub-id pub-id-type="doi">10.1111/echo.14917</pub-id>
</element-citation>
<mixed-citation>Cianciulli TF, Albarracín GA, Llobera MN, Prado NG, Saccheri MC, Vásquez YMH, et al. Speckle Tracking Echocardiography in the Indeterminate Form of Chagas Disease. Echocardiography. 2021;38(1):39-46. doi: 10.1111/echo.14917.</mixed-citation>
</ref>
<ref id="B29">
<label>29</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Romano</surname><given-names>MMD</given-names></name>
<name><surname>Moreira</surname><given-names>HT</given-names></name>
<name><surname>Marin-Neto</surname><given-names>JA</given-names></name>
<name><surname>Baccelli</surname><given-names>PE</given-names></name>
<name><surname>Alenezi</surname><given-names>F</given-names></name>
<name><surname>Klem</surname><given-names>I</given-names></name>
<etal/>
</person-group>
<article-title>Early Impairment of Myocardial Deformation Assessed by Regional Speckle-tracking Echocardiography in the Indeterminate Form of Chagas Disease without Fibrosis Detected by Cardiac Magnetic Resonance</article-title>
<source>PLoS Negl Trop Dis</source>
<year>2020</year>
<volume>14</volume>
<issue>11</issue>
<elocation-id>e0008795</elocation-id>
<pub-id pub-id-type="doi">10.1371/journal.pntd.0008795</pub-id>
</element-citation>
<mixed-citation>Romano MMD, Moreira HT, Marin-Neto JA, Baccelli PE, Alenezi F, Klem I, et al. Early Impairment of Myocardial Deformation Assessed by Regional Speckle-tracking Echocardiography in the Indeterminate Form of Chagas Disease without Fibrosis Detected by Cardiac Magnetic Resonance. PLoS Negl Trop Dis. 2020;14(11):e0008795. doi: 10.1371/journal.pntd.0008795.</mixed-citation>
</ref>
<ref id="B30">
<label>30</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Mendes</surname><given-names>VG</given-names></name>
<name><surname>Rimolo</surname><given-names>L</given-names></name>
<name><surname>Lima</surname><given-names>ACB</given-names></name>
<name><surname>Ferreira</surname><given-names>RR</given-names></name>
<name><surname>Oliveira</surname><given-names>LS</given-names></name>
<name><surname>Nisimura</surname><given-names>LM</given-names></name>
<etal/>
</person-group>
<article-title>Biomarkers and Echocardiographic Predictors of Cardiovascular Outcome in Patients with Chronic Chagas Disease</article-title>
<source>J Am Heart Assoc</source>
<year>2023</year>
<volume>12</volume>
<issue>12</issue>
<elocation-id>e028810</elocation-id>
<pub-id pub-id-type="doi">10.1161/JAHA.122.028810</pub-id>
</element-citation>
<mixed-citation>Mendes VG, Rimolo L, Lima ACB, Ferreira RR, Oliveira LS, Nisimura LM, et al. Biomarkers and Echocardiographic Predictors of Cardiovascular Outcome in Patients with Chronic Chagas Disease. J Am Heart Assoc. 2023;12(12):e028810. doi: 10.1161/JAHA.122.028810.</mixed-citation>
</ref>
<ref id="B31">
<label>31</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>García-Álvarez</surname><given-names>A</given-names></name>
<name><surname>Sitges</surname><given-names>M</given-names></name>
<name><surname>Regueiro</surname><given-names>A</given-names></name>
<name><surname>Poyatos</surname><given-names>S</given-names></name>
<name><surname>Pinazo</surname><given-names>MJ</given-names></name>
<name><surname>Posada</surname><given-names>E</given-names></name>
<etal/>
</person-group>
<article-title>Myocardial Deformation Analysis in Chagas Heart Disease with the Use of Speckle Tracking Echocardiography</article-title>
<source>J Card Fail</source>
<year>2011</year>
<volume>17</volume>
<issue>12</issue>
<fpage>1028</fpage>
<lpage>1034</lpage>
<pub-id pub-id-type="doi">10.1016/j.cardfail.2011.08.007</pub-id>
</element-citation>
<mixed-citation>García-Álvarez A, Sitges M, Regueiro A, Poyatos S, Pinazo MJ, Posada E, et al. Myocardial Deformation Analysis in Chagas Heart Disease with the Use of Speckle Tracking Echocardiography. J Card Fail. 2011;17(12):1028-34. doi: 10.1016/j.cardfail.2011.08.007.</mixed-citation>
</ref>
<ref id="B32">
<label>32</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Barbosa</surname><given-names>MM</given-names></name>
<name><surname>Rocha</surname><given-names>MOC</given-names></name>
<name><surname>Vidigal</surname><given-names>DF</given-names></name>
<name><surname>Carneiro</surname><given-names>RCB</given-names></name>
<name><surname>Araújo</surname><given-names>RD</given-names></name>
<name><surname>Palma</surname><given-names>MC</given-names></name>
<etal/>
</person-group>
<article-title>Early Detection of Left Ventricular Contractility Abnormalities by Two-dimensional Speckle Tracking Strain in Chagas’ Disease</article-title>
<source>Echocardiography</source>
<year>2014</year>
<volume>31</volume>
<issue>5</issue>
<fpage>623</fpage>
<lpage>630</lpage>
<pub-id pub-id-type="doi">10.1111/echo.12426</pub-id>
</element-citation>
<mixed-citation>Barbosa MM, Rocha MOC, Vidigal DF, Carneiro RCB, Araújo RD, Palma MC, et al. Early Detection of Left Ventricular Contractility Abnormalities by Two-dimensional Speckle Tracking Strain in Chagas’ Disease. Echocardiography. 2014;31(5):623-30. doi: 10.1111/echo.12426.</mixed-citation>
</ref>
<ref id="B33">
<label>33</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Gomes</surname><given-names>VA</given-names></name>
<name><surname>Alves</surname><given-names>GF</given-names></name>
<name><surname>Hadlich</surname><given-names>M</given-names></name>
<name><surname>Azevedo</surname><given-names>CF</given-names></name>
<name><surname>Pereira</surname><given-names>IM</given-names></name>
<name><surname>Santos</surname><given-names>CR</given-names></name>
<etal/>
</person-group>
<article-title>Analysis of Regional Left Ventricular Strain in Patients with Chagas Disease and Normal Left Ventricular Systolic Function</article-title>
<source>J Am Soc Echocardiogr</source>
<year>2016</year>
<volume>29</volume>
<issue>7</issue>
<fpage>679</fpage>
<lpage>688</lpage>
<pub-id pub-id-type="doi">10.1016/j.echo.2016.03.007</pub-id>
</element-citation>
<mixed-citation>Gomes VA, Alves GF, Hadlich M, Azevedo CF, Pereira IM, Santos CR, et al. Analysis of Regional Left Ventricular Strain in Patients with Chagas Disease and Normal Left Ventricular Systolic Function. J Am Soc Echocardiogr. 2016;29(7):679-88. doi: 10.1016/j.echo.2016.03.007.</mixed-citation>
</ref>
<ref id="B34">
<label>34</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lima</surname><given-names>MS</given-names></name>
<name><surname>Voos</surname><given-names>MC</given-names></name>
<name><surname>Mathias</surname><given-names>W</given-names><suffix>Jr</suffix></name>
<name><surname>Tsutsui</surname><given-names>JM</given-names></name>
</person-group>
<article-title>Indeterminate form of Chagas Disease: Is Left Ventricular Torsional Mechanics a Clue to Subclinical Myocardial Abnormalities?</article-title>
<source>J Echocardiogr</source>
<year>2017</year>
<volume>15</volume>
<issue>1</issue>
<fpage>6</fpage>
<lpage>12</lpage>
<pub-id pub-id-type="doi">10.1007/s12574-016-0305-5</pub-id>
</element-citation>
<mixed-citation>Lima MS, Voos MC, Mathias W Jr, Tsutsui JM. Indeterminate form of Chagas Disease: Is Left Ventricular Torsional Mechanics a Clue to Subclinical Myocardial Abnormalities? J Echocardiogr. 2017;15(1):6-12. doi: 10.1007/s12574-016-0305-5.</mixed-citation>
</ref>
<ref id="B35">
<label>35</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Santos</surname><given-names>OR</given-names><suffix>Jr</suffix></name>
<name><surname>Rocha</surname><given-names>MOC</given-names></name>
<name><surname>Almeida</surname><given-names>FR</given-names></name>
<name><surname>Cunha</surname><given-names>PFS</given-names></name>
<name><surname>Souza</surname><given-names>SCS</given-names></name>
<name><surname>Saad</surname><given-names>GP</given-names></name>
<etal/>
</person-group>
<article-title>Speckle Tracking Echocardiographic Deformation Indices in Chagas and Idiopathic Dilated Cardiomyopathy: Incremental Prognostic Value of Longitudinal Strain</article-title>
<source>PLoS One</source>
<year>2019</year>
<volume>14</volume>
<issue>8</issue>
<elocation-id>e0221028</elocation-id>
<pub-id pub-id-type="doi">10.1371/journal.pone.0221028</pub-id>
</element-citation>
<mixed-citation>Santos OR Jr, Rocha MOC, Almeida FR, Cunha PFS, Souza SCS, Saad GP, et al. Speckle Tracking Echocardiographic Deformation Indices in Chagas and Idiopathic Dilated Cardiomyopathy: Incremental Prognostic Value of Longitudinal Strain. PLoS One. 2019;14(8):e0221028. doi: 10.1371/journal.pone.0221028.</mixed-citation>
</ref>
<ref id="B36">
<label>36</label>
<element-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Echeverría</surname><given-names>LE</given-names></name>
<name><surname>Rojas</surname><given-names>LZ</given-names></name>
<name><surname>Villamizar</surname><given-names>MC</given-names></name>
<name><surname>Luengas</surname><given-names>C</given-names></name>
<name><surname>Chaves</surname><given-names>AM</given-names></name>
<name><surname>Rodríguez</surname><given-names>JA</given-names></name>
<etal/>
</person-group>
<article-title>Echocardiographic Parameters, Speckle Tracking, and Brain Natriuretic Peptide Levels as Indicators of Progression of Indeterminate Stage to Chagas Cardiomyopathy</article-title>
<source>Echocardiography</source>
<year>2020</year>
<volume>37</volume>
<issue>3</issue>
<fpage>429</fpage>
<lpage>438</lpage>
<pub-id pub-id-type="doi">10.1111/echo.14603</pub-id>
</element-citation>
<mixed-citation>Echeverría LE, Rojas LZ, Villamizar MC, Luengas C, Chaves AM, Rodríguez JA, et al. Echocardiographic Parameters, Speckle Tracking, and Brain Natriuretic Peptide Levels as Indicators of Progression of Indeterminate Stage to Chagas Cardiomyopathy. Echocardiography. 2020;37(3):429-38. doi: 10.1111/echo.14603.</mixed-citation>
</ref>
</ref-list>
</back>
<sub-article article-type="translation" id="S1" xml:lang="pt">
<front-stub>
<article-id pub-id-type="doi">10.36660/abcimg.20240053</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Artigo Original</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Função Ventricular Esquerda e Análise da Deformação Longitudinal Miocárdica em Pacientes com Doença de Chagas: Série de Casos e Revisão Sistemática da Literatura</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0002-5894-1167</contrib-id>
<name><surname>Borges</surname><given-names>José Victor da Nóbrega</given-names></name>
<role>Concepção e desenho da pesquisa</role>
<role>obtenção de dados</role>
<role>análise e interpretação dos dados</role>
<role>redação do manuscrito</role>
<role>revisão crítica do manuscrito quanto ao conteúdo intelectual importante</role>
<xref ref-type="aff" rid="aff11"><sup>1</sup></xref>
<xref ref-type="corresp" rid="c2"/>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0004-3041-0083</contrib-id>
<name><surname>Leila</surname><given-names>Samira Abdel Correia</given-names></name>
<role>Concepção e desenho da pesquisa</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<role>revisão crítica do manuscrito quanto ao conteúdo intelectual importante</role>
<xref ref-type="aff" rid="aff12"><sup>2</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0002-9043-1033</contrib-id>
<name><surname>Machado</surname><given-names>Manuella Guedes da Nóbrega</given-names></name>
<role>Concepção e desenho da pesquisa</role>
<role>obtenção de dados</role>
<role>análise estatística</role>
<role>revisão crítica do manuscrito quanto ao conteúdo intelectual importante</role>
<xref ref-type="aff" rid="aff13"><sup>3</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0004-5539-936X</contrib-id>
<name><surname>Babu</surname><given-names>Kiran Sooraj Thirukonda Jegadeesh</given-names></name>
<role>análise e interpretação dos dados</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<xref ref-type="aff" rid="aff14"><sup>4</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0001-5319-0248</contrib-id>
<name><surname>Patel</surname><given-names>Karma Jashvantbhai</given-names></name>
<role>análise e interpretação dos dados</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<xref ref-type="aff" rid="aff15"><sup>5</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0001-7136-5830</contrib-id>
<name><surname>Shah</surname><given-names>Kavya Hiteshkumar</given-names></name>
<role>análise e interpretação dos dados</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<xref ref-type="aff" rid="aff15"><sup>5</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0003-5030-8863</contrib-id>
<name><surname>Takkasila</surname><given-names>Mahitha Reddy</given-names></name>
<role>análise e interpretação dos dados</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<xref ref-type="aff" rid="aff16"><sup>6</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0005-6269-0136</contrib-id>
<name><surname>Shaik</surname><given-names>Abdul Majid</given-names></name>
<role>análise e interpretação dos dados</role>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<xref ref-type="aff" rid="aff17"><sup>7</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0005-0829-1521</contrib-id>
<name><surname>Shaikh</surname><given-names>Muhammad Ahmed</given-names></name>
<role>análise estatística</role>
<role>redação do manuscrito</role>
<role>revisão crítica do manuscrito quanto ao conteúdo intelectual importante</role>
<xref ref-type="aff" rid="aff18"><sup>8</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0000-0003-3584-6500</contrib-id>
<name><surname>Khandekar</surname><given-names>Ninad</given-names></name>
<xref ref-type="aff" rid="aff19"><sup>9</sup></xref>
</contrib>
<contrib contrib-type="author">
<contrib-id contrib-id-type="orcid">0009-0006-5021-0446</contrib-id>
<name><surname>Burra</surname><given-names>Sahithi</given-names></name>
<role>análise e interpretação dos dados</role>
<role>redação do manuscrito</role>
<role>revisão crítica do manuscrito quanto ao conteúdo intelectual importante</role>
<xref ref-type="aff" rid="aff20"><sup>10</sup></xref>
</contrib>
<aff id="aff11">
<label>1</label>
<addr-line>
<named-content content-type="city">São Paulo</named-content>
<named-content content-type="state">SP</named-content>
</addr-line>
<country country="BR">Brasil</country>
<institution content-type="original">Universidade de São Paulo, Instituto do Coração, São Paulo, SP – Brasil</institution>
</aff>
<aff id="aff12">
<label>2</label>
<addr-line>
<named-content content-type="city">São Paulo</named-content>
<named-content content-type="state">SP</named-content>
</addr-line>
<country country="BR">Brasil</country>
<institution content-type="original">Hospital Israelita Albert Einstein, São Paulo, SP – Brasil</institution>
</aff>
<aff id="aff13">
<label>3</label>
<addr-line>
<named-content content-type="city">Vilhena</named-content>
<named-content content-type="state">RO</named-content>
</addr-line>
<country country="BR">Brasil</country>
<institution content-type="original">Clínica Central de Diagnóstico, Vilhena, RO – Brasil</institution>
</aff>
<aff id="aff14">
<label>4</label>
<addr-line>
<named-content content-type="city">Sri Ramachandra</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Sri Ramachandra Institute of Higher Education and Research, Sri Ramachandra – Índia</institution>
</aff>
<aff id="aff15">
<label>5</label>
<addr-line>
<named-content content-type="city">Valsad</named-content>
<named-content content-type="state">Gujarat</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Gujarat Medical Education and Research Society, Medical College &amp; Hospital Valsad, Valsad, Gujarat – Índia</institution>
</aff>
<aff id="aff16">
<label>6</label>
<addr-line>
<named-content content-type="city">Manipal</named-content>
<named-content content-type="state">Karnataka</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Kasturba Medical College Manipal, Manipal, Karnataka – Índia</institution>
</aff>
<aff id="aff17">
<label>7</label>
<addr-line>
<named-content content-type="city">Warangal</named-content>
<named-content content-type="state">Telangana</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Kakatiya Medical College, Warangal, Telangana – Índia</institution>
</aff>
<aff id="aff18">
<label>8</label>
<addr-line>
<named-content content-type="city">Karachi</named-content>
<named-content content-type="state">Sindh</named-content>
</addr-line>
<country country="PK">Paquistão</country>
<institution content-type="original">Jinnah Sindh Medical University, Karachi, Sindh – Paquistão</institution>
</aff>
<aff id="aff19">
<label>9</label>
<addr-line>
<named-content content-type="city">Thiruvananthapuram</named-content>
<named-content content-type="state">Kerala</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Government Medical College and Hospital, Thiruvananthapuram, Kerala – Índia</institution>
</aff>
<aff id="aff20">
<label>10</label>
<addr-line>
<named-content content-type="city">Hyderabad</named-content>
<named-content content-type="state">Telangana</named-content>
</addr-line>
<country country="IN">Índia</country>
<institution content-type="original">Osmania Medical College, Hyderabad, Telangana – Índia</institution>
</aff>
</contrib-group>
<author-notes>
<corresp id="c2"><label>Correspondência:</label> <bold>José Victor da Nóbrega Borges</bold> • Instituto de Assistência Médica ao Servidor Público Estadual, Clínica Médica. Avenida Ibiapuera, 981. CEP: <postal-code>04084-009</postal-code>. São Paulo, SP – Brasil E-mail: <email>josenborges@gmail.com</email></corresp>
<fn fn-type="conflict"><label>Potencial Conflito de Interesse</label><p>Declaro não haver conflito de interesses pertinentes.</p></fn>
<fn fn-type="edited-by"><label>Editor responsável pela revisão:</label><p>Marcelo Tavares</p></fn>
</author-notes>
<abstract>
<title>Resumo</title>
<sec>
<title>Introdução:</title>
<p>Disfunção ventricular esquerda como preditor independente de mortalidade na doença de Chagas. A deformação longitudinal global (DLG) é uma modalidade ecocardiográfica emergente com possível valor incremental na detecção precoce de envolvimento cardíaco.</p>
</sec>
<sec>
<title>Objetivo:</title>
<p>Comparar a função ventricular esquerda com múltiplos parâmetros ecocardiográficos entre pacientes com formas indeterminadas e crônicas de Chagas, e realizar uma revisão da literatura.</p>
</sec>
<sec>
<title>Metodologia:</title>
<p>Neste estudo observacional, 11 pacientes com diagnóstico confirmado de doença de Chagas foram avaliados. Os indivíduos foram distribuídos da seguinte forma: cinco com as formas indeterminadas e seis com as formas crônicas. A avaliação ecocardiográfica convencional foi acompanhada pela medida da DLG.</p>
</sec>
<sec>
<title>Resultados:</title>
<p>A média da fração de ejeção do ventrículo esquerdo (FEVE) foi de 33 ± 2,88 e a DLG média do ventrículo esquerdo foi de −10,76 ± 2,20 na forma crônica, em comparação com 57,80 ± 6,49 e −17,34 ± 3,82, respectivamente no grupo indeterminado. A contratilidade foi reduzida em segmentos das paredes inferior, inferoseptal e ântero-septal em ambos os grupos. Essas alterações segmentares no grupo indeterminado podem ser atribuídas ao dano miocárdico precoce por inflamação e fibrose, mesmo antes de uma disfunção ventricular esquerda significativa se tornar evidente.</p>
</sec>
<sec>
<title>Conclusão:</title>
<p>A análise da deformação longitudinal na forma indeterminada tem potencial valor incremental à análise convencional da fração de ejeção quando comparada a pacientes com cardiomiopatia chagásica crônica, principalmente com a análise segmentar individual, mas o impacto e o significado clínico dessas técnicas ainda são desconhecidos.</p>
</sec>
</abstract>
<kwd-group xml:lang="pt">
<title>Palavras-chave:</title>
<kwd>Cardiomiopatia Chagásica</kwd>
<kwd>Deformação Longitudinal Global</kwd>
<kwd>Função Ventricular Esquerda</kwd>
</kwd-group>
</front-stub>
<body>
<fig id="f6">
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf00-pt.tif"/>
<attrib>VE: ventrículo esquerdo; FEVE: fração de ejeção do ventrículo esquerdo; DLG: deformação longitudinal global.</attrib>
</fig>
<sec sec-type="intro">
<title>Introdução</title>
<p>A doença de Chagas é uma das principais causas de doenças tropicais no Novo Mundo, com uma carga maior do que qualquer outra doença parasitária nas Américas.<sup><xref ref-type="bibr" rid="B1">1</xref></sup> A doença é causada pela infecção pelo <italic>Trypanosoma cruzi</italic> (T. cruzi), um protozoário hemoflagelado parasita transmitido principalmente por insetos triatomíneos que se alimentam de sangue humano e animal. A partir das fezes dos insetos, o parasita passa por essas fissuras na pele ou mucosa causando infecção. Ainda que raramente, pode ser transmitida de forma congênita, através de transplante de órgãos ou alimentos e água contaminados.<sup><xref ref-type="bibr" rid="B2">2</xref></sup> As diferentes rotas de transmissão variam entre as áreas geográficas. Descrita pela primeira vez em 1909 por Carlos Chagas, que lhe deu o nome, a doença foi inicialmente confinada à América Latina, onde é endêmica.<sup><xref ref-type="bibr" rid="B3">3</xref></sup> Embora a transmissão vetorial tenha sido controlada até certo ponto em áreas anteriormente endêmicas, com as atuais tendências de migração, a prevalência também aumentou nos Estados Unidos, na Europa e no Japão.<sup><xref ref-type="bibr" rid="B4">4</xref></sup> Em 2019, a prevalência global da doença de Chagas foi estimada em 6.469.283, representando uma diminuição de 11,3% na prevalência nas três décadas anteriores a 1990. No entanto, essa redução foi acompanhada por um aumento na prevalência em países não endêmicos. A Espanha teve o maior aumento absoluto de casos estimados, seguida pelos Estados Unidos e pela Itália.<sup><xref ref-type="bibr" rid="B5">5</xref></sup> Este aumento deve-se, principalmente, ao movimento populacional de indivíduos já infectados de áreas endêmicas, em contraste com a raridade da transmissão por vetores em países não endêmicos.<sup><xref ref-type="bibr" rid="B6">6</xref></sup> Apenas 16 infecções foram presumivelmente adquiridas por transmissão autóctone, transmitida por vetores nos Estados Unidos entre 1955 e 2012.<sup><xref ref-type="bibr" rid="B7">7</xref>,<xref ref-type="bibr" rid="B8">8</xref></sup> O teste de reação em cadeia da polimerase (PCR) é a opção mais sensível no diagnóstico da infecção aguda de Chagas, incluindo o monitoramento de pacientes transplantados de órgãos de doadores infectados por T. cruzi e pacientes imunocomprometidos.<sup><xref ref-type="bibr" rid="B9">9</xref></sup> Para confirmar a doença de Chagas crônica são necessários pelo menos dois testes sorológicos de detecção de anticorpos com métodos diferentes.<sup><xref ref-type="bibr" rid="B10">10</xref>,<xref ref-type="bibr" rid="B11">11</xref></sup> A imunofluorescência indireta, o ensaio imunoenzimático (ELISA) e a hemaglutinação são os métodos mais comumente utilizados.<sup><xref ref-type="bibr" rid="B12">12</xref>,<xref ref-type="bibr" rid="B13">13</xref></sup> Na fase aguda, os pacientes são frequentemente assintomáticos ou apresentam sintomas leves, como febre, fadiga e erupção cutânea, enquanto a forma crônica geralmente se apresenta com manifestações gastrointestinais e, nas formas mais graves, cardiomiopatia, incluindo insuficiência cardíaca, arritmias e morte súbita cardíaca (MSC). Disfunção ventricular esquerda como preditor independente de mortalidade na doença de Chagas. A disfunção sistólica é frequentemente precedida por manifestações subclínicas. Na fase indeterminada, apesar da ausência de doença cardíaca clínica, o envolvimento miocárdico pode ser detectado através de exames de imagem. Estudos sugerem que alterações inflamatórias precoces e fibrose afetam principalmente os segmentos inferoseptal, inferior e ântero-septal, o que pode explicar as alterações de contratilidade segmentar observadas em nosso estudo. A deformação longitudinal global (DLG) é uma modalidade não invasiva derivada da ecocardiografia bidimensional speckle tracking (STE).<sup><xref ref-type="bibr" rid="B14">14</xref></sup> A avaliação da STE, juntamente com a ecocardiografia convencional, demonstrou detectar anormalidades subclínicas da deformação miocárdica do ventrículo esquerdo, mesmo antes de uma redução profunda na fração de ejeção do ventrículo esquerdo (FEVE) ser evidente na cardiomiopatia chagásica.<sup><xref ref-type="bibr" rid="B15">15</xref>,<xref ref-type="bibr" rid="B16">16</xref></sup> Essa técnica surge como preditor significativo de eventos cardiovasculares adversos em pacientes com a forma indeterminada da doença.<sup><xref ref-type="bibr" rid="B17">17</xref></sup></p>
</sec>
<sec sec-type="methods">
<title>Metodologia</title>
<p>Um estudo observacional transversal de 11 pacientes com diagnóstico confirmado.</p>
<p>O diagnóstico da doença de Chagas foi realizado em um hospital especializado terciário no Brasil. Os pacientes foram submetidos à análise detalhada do histórico médico, exame físico, eletrocardiograma (ECG) de repouso e ecocardiograma bidimensional convencional com Doppler seguido de análise DLG usando speckle tracking. Os pacientes foram avaliados por meio de ecocardiografia para avaliar a contratilidade segmentar. A contratilidade segmentar foi analisada especificamente nas paredes inferior, inferoseptal e ântero-septal devido à sua conhecida vulnerabilidade ao dano miocárdico precoce na doença de Chagas. Estudos anteriores indicaram que a inflamação e a fibrose afetam predominantemente essas regiões, mesmo na fase indeterminada. Técnicas avançadas de imagem, como a ecocardiografia com speckle-tracking, têm demonstrado essas disfunções segmentares em pacientes assintomáticos, destacando o impacto precoce da doença sobre o miocárdio. Os participantes tinham idade média de 76,36 +/- 6,26 anos e o consentimento informado por escrito foi obtido para o uso de dados clínicos para cada indivíduo no estudo. Os pacientes foram classificados nas formas indeterminada (45%) e cardíaca (55%) da doença de Chagas.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> Os pacientes com cardiomiopatia chagásica foram classificados nos estágios B1, B2, C e D.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> B1 é definido como alterações estruturais observadas no ECG ou ecocardiografia com função ventricular global normal e sem sintomas de insuficiência cardíaca. O estágio B2 mostra cardiomiopatia estrutural com disfunção ventricular, mas sem sintomas presentes ou passados de insuficiência cardíaca. O estágio C é definido como pacientes com disfunção ventricular e sintomas presentes ou passados de insuficiência cardíaca (todas as classes da New York Heart Association, NYHA) e o estágio D é a insuficiência cardíaca refratária ao tratamento que requer intervenções especializadas. Os pacientes foram submetidos à confirmação sorológica por ELISA anti-T. cruzi ligado a enzima (Ortho Clinical Diagnostic, EUA) e ensaio de hemaglutinação indireta (IHA) (Polychaco, Lemos Laboratory SRL, Argentina). A ecocardiografia foi realizada com aparelho Philips Epiq 7C com transdutor setorial de 3,4 MHz. As medições dos parâmetros ventriculares esquerdos foram realizadas de acordo com as recomendações da Sociedade Americana de Ecocardiografia e da Associação Europeia de Imagens Cardiovasculares.<sup><xref ref-type="bibr" rid="B19">19</xref></sup> A FEVE foi calculada pelo método biplano de Simpson modificado, utilizando os cortes apicais de quatro e duas câmaras. A análise da deformação segmentar e longitudinal do ventrículo esquerdo foi realizada utilizando o sistema QLAB (Philips, Países Baixos). Uma revisão de escopo da literatura foi realizada nas principais bases de dados das ciências médicas, incluindo Pubmed e Scopus. Os critérios de inclusão de palavras-chave foram selecionados para o seguinte: cardiomiopatia chagásica e DLG do ventrículo esquerdo. Os resultados foram filtrados para incluir relatos de casos de humanos com doença de Chagas em texto completo, escritos em inglês. Um total de 25 registros foram obtidos durante a busca inicial. Dois revisores examinaram os títulos e resumos para determinar se atendiam aos critérios de inclusão. Durante a triagem, 12 registros foram excluídos. Um total de 13 registros seguiram para a avaliação do texto completo. Quatro revisores avaliaram o conteúdo dos relatos de casos para determinar se incluíam informações suficientes sobre os pacientes e sua doença. As características basais e os parâmetros ecocardiográficos dos pacientes incluídos no estudo são apresentados na <xref ref-type="table" rid="t6">Tabela 1</xref>.</p>
<table-wrap id="t6">
<label>Tabela 1</label>
<caption><title>Características basais e parâmetros ecocardiográficos dos pacientes incluídos no estudo</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="5%">
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">N.° do Paciente</th>
<th align="center" valign="middle">Idade (anos)</th>
<th align="center" valign="middle">Área de superfície corporal (metro quadrado)</th>
<th align="center" valign="middle">FEVE (%)</th>
<th align="center" valign="middle">Índice de volume AE (ml metro quadrado)</th>
<th align="center" valign="middle">Peso do VE (g)</th>
<th align="center" valign="middle">VSF VE (ml)</th>
<th align="center" valign="middle">VDF VE (ml)</th>
<th align="center" valign="middle">DLG VE (%)</th>
<th align="center" valign="middle">DL SEPT-ANT (%)</th>
<th align="center" valign="middle">DL ANT (%)</th>
<th align="center" valign="middle">DL ANT-LAT (%)</th>
<th align="center" valign="middle">DL INF-LAT (%)</th>
<th align="center" valign="middle">DL INF (%)</th>
<th align="center" valign="middle">DL INF-SEPT</th>
<th align="center" valign="middle">Relação E-e’</th>
<th align="center" valign="middle">dSVE (mm)</th>
<th align="center" valign="middle">dDVE (mm)</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="center" valign="middle"><bold>1</bold></td>
<td align="center" valign="middle">74,5</td>
<td align="center" valign="middle">1,698</td>
<td align="center" valign="middle">31</td>
<td align="center" valign="middle">79,51</td>
<td align="center" valign="middle">277</td>
<td align="center" valign="middle">127</td>
<td align="center" valign="middle">186</td>
<td align="center" valign="middle">-14,2</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-17</td>
<td align="center" valign="middle">20,4</td>
<td align="center" valign="middle">51,6</td>
<td align="center" valign="middle">60,8</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>2</bold></td>
<td align="center" valign="middle">71,58</td>
<td align="center" valign="middle">1,555</td>
<td align="center" valign="middle">28</td>
<td align="center" valign="middle">58,96</td>
<td align="center" valign="middle">185,28</td>
<td align="center" valign="middle">152</td>
<td align="center" valign="middle">195</td>
<td align="center" valign="middle">-7,1</td>
<td align="center" valign="middle">-5</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-4</td>
<td align="center" valign="middle">-7</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">38</td>
<td align="center" valign="middle">55,8</td>
<td align="center" valign="middle">62,2</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>3</bold></td>
<td align="center" valign="middle">67,66</td>
<td align="center" valign="middle">1,674</td>
<td align="center" valign="middle">51</td>
<td align="center" valign="middle">34,29</td>
<td align="center" valign="middle">377</td>
<td align="center" valign="middle">116</td>
<td align="center" valign="middle">234</td>
<td align="center" valign="middle">-11,2</td>
<td align="center" valign="middle">-16</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">10</td>
<td align="center" valign="middle">49,5</td>
<td align="center" valign="middle">67,3</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>4</bold></td>
<td align="center" valign="middle">67,16</td>
<td align="center" valign="middle">1,664</td>
<td align="center" valign="middle">65</td>
<td align="center" valign="middle">40,21</td>
<td align="center" valign="middle">310</td>
<td align="center" valign="middle">53</td>
<td align="center" valign="middle">152</td>
<td align="center" valign="middle">-22,2</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-24</td>
<td align="center" valign="middle">-26</td>
<td align="center" valign="middle">-21</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">13</td>
<td align="center" valign="middle">35,7</td>
<td align="center" valign="middle">55,7</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>5</bold></td>
<td align="center" valign="middle">78,33</td>
<td align="center" valign="middle">1,73</td>
<td align="center" valign="middle">33</td>
<td align="center" valign="middle">62,41</td>
<td align="center" valign="middle">366</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">190</td>
<td align="center" valign="middle">-9,8</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-6</td>
<td align="center" valign="middle">31,33</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">61,5</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>6</bold></td>
<td align="center" valign="middle">83,58</td>
<td align="center" valign="middle">1,791</td>
<td align="center" valign="middle">34</td>
<td align="center" valign="middle">41,2</td>
<td align="center" valign="middle">302</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">190</td>
<td align="center" valign="middle">-12,1</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-11</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">19,75</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">61,4</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>7</bold></td>
<td align="center" valign="middle">77,83</td>
<td align="center" valign="middle">1,492</td>
<td align="center" valign="middle">62</td>
<td align="center" valign="middle">23,13</td>
<td align="center" valign="middle">209</td>
<td align="center" valign="middle">49</td>
<td align="center" valign="middle">149</td>
<td align="center" valign="middle">-18,5</td>
<td align="center" valign="middle">-23</td>
<td align="center" valign="middle">-20</td>
<td align="center" valign="middle">-22</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-14</td>
<td align="center" valign="middle">-16</td>
<td align="center" valign="middle">9,8</td>
<td align="center" valign="middle">34,6</td>
<td align="center" valign="middle">55,3</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>8</bold></td>
<td align="center" valign="middle">85,5</td>
<td align="center" valign="middle">1,528</td>
<td align="center" valign="middle">35</td>
<td align="center" valign="middle">52,28</td>
<td align="center" valign="middle">257</td>
<td align="center" valign="middle">133</td>
<td align="center" valign="middle">204</td>
<td align="center" valign="middle">-9,9</td>
<td align="center" valign="middle">-8</td>
<td align="center" valign="middle">-7</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-12</td>
<td align="center" valign="middle">-4</td>
<td align="center" valign="middle">-9</td>
<td align="center" valign="middle">24</td>
<td align="center" valign="middle">52,6</td>
<td align="center" valign="middle">63,4</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>9</bold></td>
<td align="center" valign="middle">70,33</td>
<td align="center" valign="middle">2,151</td>
<td align="center" valign="middle">49</td>
<td align="center" valign="middle">38,5</td>
<td align="center" valign="middle">287</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">194</td>
<td align="center" valign="middle">-15,1</td>
<td align="center" valign="middle">-17</td>
<td align="center" valign="middle">-15</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-10</td>
<td align="center" valign="middle">-12</td>
<td align="center" valign="middle">13</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">63</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="center" valign="middle"><bold>10</bold></td>
<td align="center" valign="middle">79,58</td>
<td align="center" valign="middle">1,932</td>
<td align="center" valign="middle">62</td>
<td align="center" valign="middle">27,33</td>
<td align="center" valign="middle">240</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">140</td>
<td align="center" valign="middle">-19,7</td>
<td align="center" valign="middle">-13</td>
<td align="center" valign="middle">-27</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">-18</td>
<td align="center" valign="middle">-21</td>
<td align="center" valign="middle">-19</td>
<td align="center" valign="middle">18</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">53,7</td>
</tr>
<tr>
<td align="center" valign="middle"><bold>11</bold></td>
<td align="center" valign="middle">83,91</td>
<td align="center" valign="middle">1,637</td>
<td align="center" valign="middle">37</td>
<td align="center" valign="middle">58,84</td>
<td align="center" valign="middle">381</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">201</td>
<td align="center" valign="middle">-11,5</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle"/>
<td align="center" valign="middle">65</td>
<td align="center" valign="middle"/>
<td align="center" valign="middle">63</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN6"><p>AE: átrio esquerdo; VE: ventrículo esquerdo; FEVE: fração de ejeção do ventrículo esquerdo; VSF VE: volume sistólico final do ventrículo esquerdo; VDF VE: volume diastólico final do ventrículo esquerdo; DLG VE: deformação longitudinal global do ventrículo esquerdo; DL SEPT ANT: deformação longitudinal septal anterior; DL ANT: deformação longitudinal anterior; DL ANT-LAT: deformação longitudinal anterolateral; DL INF-LAT: deformação longitudinal inferior-lateral; DL INF: deformação longitudinal inferior; DL INF-SEPT: deformação longitudinal inferior-septal; relação E-e’: razão entre a velocidade do fluxo transmitral inicial (E) e a velocidade diastólica inicial do tecido (e’) na ecocardiografia; dSVE: diâmetro do septo ventricular esquerdo; dDVE: diâmetro diastólico do ventrículo esquerdo.</p></fn>
</table-wrap-foot>
</table-wrap>
<sec>
<title>Apresentação da série de casos</title>
<p>Este estudo observacional transversal incluiu 11 participantes selecionados de uma coorte de pacientes com doença de Chagas, acompanhados em um centro terciário no Brasil, sendo sete homens (63,34%) e quatro mulheres (36,36%), que foram divididos nas formas crônica (55%) e indeterminada (45%). A média de idade dos participantes foi de 76,36 ± 6,26 anos com média de idade de 79,56 ± 5,16 no grupo crônico e 72,51 ± 5,19 no grupo indeterminado. Em termos de classificação da gravidade da doença, os pacientes nas fases crônica e indeterminada foram classificados como estágios B1 e C, respectivamente.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> A avaliação clínica incluiu análise detalhada do histórico médico, exame físico, ECG de repouso e ecocardiograma bidimensional convencional com Doppler seguido de análise DLG usando speckle tracking. O consentimento por escrito foi obtido dos participantes do estudo e, embora nenhuma intervenção direta tenha sido promovida, a análise proposta também foi aprovada pelo conselho de revisão de ética institucional. Os pacientes da forma indeterminada foram inicialmente triados e testados para doença de Chagas devido a sintomas generalizados ou história epidemiológica sugestiva sem doença cardiovascular no momento do diagnóstico. Os pacientes da forma crônica apresentavam sintomas clássicos de insuficiência cardíaca, como edema bilateral de membros inferiores, falta de ar aos esforços e dispneia paroxística noturna. Três dos seis pacientes (50%) da forma crônica estavam em classe II da NYHA, dois pacientes em classe III da NYHA e um paciente em classe I da NYHA, taquicardia ventricular não sustentada (TVNS) registrada no Holter de 24 horas (<xref ref-type="fig" rid="f4">Figura 1</xref>). Os valores médios dos parâmetros ecocardiográficos e basais para todos os indivíduos são apresentados na <xref ref-type="table" rid="t7">Tabela 2</xref>. No momento do diagnóstico, a confirmação sorológica por ELISA anti-T. cruzi (Ortho Clinical Diagnostic, EUA) e IHA (Polychaco, Lemos Laboratory SRL, Argentina). Todos os pacientes foram tratados de acordo com as diretrizes mais recentes para cardiomiopatias.</p>
<fig id="f4">
<label>Figura 1</label>
<caption>
<title>Documentação de TVNS no Holter de 24 horas para um dos pacientes com a forma crônica da doença.</title></caption>
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf01-pt.tif"/>
</fig>
<table-wrap id="t7">
<label>Tabela 2</label>
<caption><title>Valores médios de todos os participantes</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variável</th>
<th align="center" valign="middle">Valor</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">11</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Sexo masculino (%)</td>
<td align="center" valign="middle">63,64</td>
</tr>
<tr>
<td align="left" valign="middle">Sexo feminino (%)</td>
<td align="center" valign="middle">36,36</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Idade (anos)</td>
<td align="center" valign="middle">76,36 ± 6,26</td>
</tr>
<tr>
<td align="left" valign="middle">Área de superfície corporal (metro quadrado)</td>
<td align="center" valign="middle">1,7138 ± 0,1819</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">FEVE (%)</td>
<td align="center" valign="middle">44,27 ± 13,27</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Índice de volume AE (ml metro quadrado)</td>
<td align="center" valign="middle">46,96 ± 16,16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Peso do VE (g)</td>
<td align="center" valign="middle">290,11 ± 62,85</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">dSVE (mm)</td>
<td align="center" valign="middle">46,63 ± 9,13</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">dDVE (mm)</td>
<td align="center" valign="middle">60,66 ± 3,90</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">VSF VE (ml)</td>
<td align="center" valign="middle">105 ± 43,44</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">VDF VE (ml)</td>
<td align="center" valign="middle">185 ± 26,38</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Relação E-e’</td>
<td align="center" valign="middle">23,84 ± 15,48</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL SEPT-ANT (%)</td>
<td align="center" valign="middle">-13,20 ± 5,21</td>
</tr>
<tr>
<td align="left" valign="middle">DL ANT</td>
<td align="center" valign="middle">-14,90 ± 6,72</td>
</tr>
<tr>
<td align="left" valign="middle">DL ANT-LAT (%)</td>
<td align="center" valign="middle">-15,30 ± 6,45</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL INF-LAT (%)</td>
<td align="center" valign="middle">-14,63 ± 5,04</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL INF</td>
<td align="center" valign="middle">-12,20 ± 5,61</td>
</tr>
<tr>
<td align="left" valign="middle">DL SEPT-INF (%)</td>
<td align="center" valign="middle">-12,10 ± 5,68</td>
</tr>
<tr>
<td align="left" valign="middle">DLG VE (%)</td>
<td align="center" valign="middle">-13,75 ± 4,47</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN7"><p>AE: átrio esquerdo; VE: ventrículo esquerdo; FEVE: fração de ejeção do ventrículo esquerdo; VSF VE: volume sistólico final do ventrículo esquerdo; VDF VE: volume diastólico final do ventrículo esquerdo; DLG VE: deformação longitudinal global do ventrículo esquerdo; DL SEPT ANT: deformação longitudinal septal anterior; DL ANT: deformação longitudinal anterior; DL ANT-LAT: deformação longitudinal anterolateral; DL INF-LAT: deformação longitudinal inferior-lateral; DL INF: deformação longitudinal inferior; dSVE: diâmetro do septo ventricular esquerdo; dDVE: diâmetro diastólico do ventrículo esquerdo; DL SEPT-INF : deformação longitudinal septal inferior.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>A análise ecocardiográfica foi realizada e revisada por dois ecocardiografistas certificados usando Philips Epiq 7C com um transdutor setorial de 3,4 MHz. As medições foram realizadas de acordo com as diretrizes da Sociedade Americana de Ecocardiografia e da Associação Europeia de Imagens Cardiovasculares.<sup><xref ref-type="bibr" rid="B19">19</xref></sup> A FEVE foi calculada pelo método biplano de Simpson modificado, utilizando os cortes apicais de quatro e duas câmaras. A análise da deformação segmentar e longitudinal do ventrículo esquerdo foi calculada utilizando o sistema semiautomático QLAB (Philips, Holanda), que considerou valores normais &gt; −18%. Os valores médios dos parâmetros ecocardiográficos, divididos por grupos, são apresentados na <xref ref-type="table" rid="t8">Tabela 3</xref> (forma crônica) e <xref ref-type="table" rid="t9">Tabela 4</xref> (forma indeterminada). O volume sistólico final e o diâmetro sistólico do ventrículo esquerdo de alguns pacientes não foram obtidos devido a dificuldades técnicas e, portanto, não foram incluídos nos dados apresentados.</p>
<table-wrap id="t8">
<label>Tabela 3</label>
<caption><title>Valores médios dos participantes com forma crônica</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variável</th>
<th align="center" valign="middle">Valor</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">6</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Idade</td>
<td align="center" valign="middle">79,56 ± 5,18</td>
</tr>
<tr>
<td align="left" valign="middle">Área de superfície corporal (metro quadrado)</td>
<td align="center" valign="middle">1,6565 ± 0,1024</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">FEVE (0/0)</td>
<td align="center" valign="middle">33 ± 2,88</td>
</tr>
<tr>
<td align="left" valign="middle">Índice de volume AE (ml metro quadrado)</td>
<td align="center" valign="middle">58,87 ± 12,60</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Peso do VE (g)</td>
<td align="center" valign="middle">294,71 ± 72,51</td>
</tr>
<tr>
<td align="left" valign="middle">dSVE (mm)</td>
<td align="center" valign="middle">53,33 ± 2,19</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">dDVE (mm)</td>
<td align="center" valign="middle">62,05 ± 1,00</td>
</tr>
<tr>
<td align="left" valign="middle">VSF VE (ml)</td>
<td align="center" valign="middle">137,33 ± 13,05</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">VDF VE (ml)</td>
<td align="center" valign="middle">194,33 ± 7,005</td>
</tr>
<tr>
<td align="left" valign="middle">Relação E-e’</td>
<td align="center" valign="middle">33,08 ± 17,13</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL SEPT-ANT</td>
<td align="center" valign="middle">-9,83 ± 3,54</td>
</tr>
<tr>
<td align="left" valign="middle">DL ANT</td>
<td align="center" valign="middle">-10,83 ± 4,16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL ANT-LAT</td>
<td align="center" valign="middle">-11,16 ± 5,38</td>
</tr>
<tr>
<td align="left" valign="middle">DL INF-LAT (%)</td>
<td align="center" valign="middle">-12,83 ± 5,49</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL INF (%)</td>
<td align="center" valign="middle">-8,33 ± 4,03</td>
</tr>
<tr>
<td align="left" valign="middle">DL SEPT-INF</td>
<td align="center" valign="middle">-8,83 ± 4,16</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DLG VE (%)</td>
<td align="center" valign="middle">10,76 ± 2,20</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN8"><p>AE: átrio esquerdo; VE: ventrículo esquerdo; FEVE: fração de ejeção do ventrículo esquerdo; VSF VE: volume sistólico final do ventrículo esquerdo; VDF VE: volume diastólico final do ventrículo esquerdo; DLG VE: deformação longitudinal global do ventrículo esquerdo; DL SEPT ANT: deformação longitudinal septal anterior; DL ANT: deformação longitudinal anterior; DL ANT-LAT: deformação longitudinal anterolateral; DL INF-LAT: deformação longitudinal inferior-lateral; DL INF: deformação longitudinal inferior; dSVE: diâmetro do septo ventricular esquerdo; dDVE: diâmetro diastólico do ventrículo esquerdo; DL SEPT-INF: deformação longitudinal septal inferior.</p></fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="t9">
<label>Tabela 4</label>
<caption><title>Valores médios dos participantes com forma indeterminada</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="50%">
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Variável</th>
<th align="center" valign="middle">Valor</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">N</td>
<td align="center" valign="middle">5</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Idade</td>
<td align="center" valign="middle">72,51 ± 5,19</td>
</tr>
<tr>
<td align="left" valign="middle">Área de superfície corporal (metro quadrado)</td>
<td align="center" valign="middle">1,7826 ± 0,26</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">FEVE (0/0)</td>
<td align="center" valign="middle">57,80 ± 6.49</td>
</tr>
<tr>
<td align="left" valign="middle">Índice de volume AE (ml metro quadrado)</td>
<td align="center" valign="middle">32,69 ± 7,29</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Peso do VE (g)</td>
<td align="center" valign="middle">284,6 ± 64,98</td>
</tr>
<tr>
<td align="left" valign="middle">dSVE (mm)</td>
<td align="center" valign="middle">39,93 ± 8,30</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">dDVE (mm)</td>
<td align="center" valign="middle">59 ± 5,86</td>
</tr>
<tr>
<td align="left" valign="middle">VSF VE (ml)</td>
<td align="center" valign="middle">72,67 ± 37,58</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">VDF VE (ml)</td>
<td align="center" valign="middle">173,8 ± 39,57</td>
</tr>
<tr>
<td align="left" valign="middle">Relação E-e’</td>
<td align="center" valign="middle">12,76 ± 3,31</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL SEPT-ANT</td>
<td align="center" valign="middle">-17,4 ± 3,65</td>
</tr>
<tr>
<td align="left" valign="middle">DL ANT</td>
<td align="center" valign="middle">-19,4 ± 6,50</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL ANT-LAT</td>
<td align="center" valign="middle">-19 ± 5,92</td>
</tr>
<tr>
<td align="left" valign="middle">DL INF-LAT (%)</td>
<td align="center" valign="middle">-16,8 ± 3,89</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DL INF (%)</td>
<td align="center" valign="middle">-15,6 ± 5.59</td>
</tr>
<tr>
<td align="left" valign="middle">DL SEPT-INF</td>
<td align="center" valign="middle">-15 ± 6,24</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">DLG VE (%)</td>
<td align="center" valign="middle">17,34 ± 3,82</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN9"><p>AE: átrio esquerdo; VE: ventrículo esquerdo; FEVE: fração de ejeção do ventrículo esquerdo; VSF VE: volume sistólico final do ventrículo esquerdo; VDF VE: volume diastólico final do ventrículo esquerdo; DLG VE: deformação longitudinal global do ventrículo esquerdo; DL SEPT ANT: deformação longitudinal septal anterior; DL ANT: deformação longitudinal anterior; DL ANT-LAT: deformação longitudinal anterolateral; DL INF-LAT: deformação longitudinal inferior-lateral; DL INF: deformação longitudinal inferior; dSVE: diâmetro do septo ventricular esquerdo; dDVE: diâmetro diastólico do ventrículo esquerdo; DL SEPT-INF : deformação longitudinal septal inferior.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>A média da FEVE foi de 33 ± 2,88 e a DLG média do ventrículo esquerdo foi de −10,76 ± 2,20 na forma crônica, em comparação com 57,80 ± 6,49 e −17,34 ± 3,82, respectivamente no grupo indeterminado. Em relação à deformação segmentar do ventrículo esquerdo, cada segmento foi avaliado individualmente em cada grupo. A análise da deformidade miocárdica pelo speckle tracking foi significativamente reduzida em todos os segmentos das paredes inferior, inferoseptal e ântero-septal em ambas as categorias (<xref ref-type="fig" rid="f5">Figura 2</xref>). Esses resultados estão em conformidade com a literatura, que sugere que essas áreas são suscetíveis a alterações inflamatórias precoces e fibrose na fase indeterminada da doença de Chagas, que podem ocorrer antes de uma manifestação significativa de disfunção ventricular esquerda. Estudos anteriores identificaram essas anormalidades segmentares como indicadores precoces de dano miocárdico, mesmo na ausência de sintomas clínicos evidentes.<sup><xref ref-type="bibr" rid="B17">17</xref>,<xref ref-type="bibr" rid="B18">18</xref></sup></p>
<fig id="f5">
<label>Figura 2</label>
<caption>
<title>Conforme representado no alvo, a contratilidade segmentar do ventrículo esquerdo, analisada pela deformação bidimensional derivada do STE, foi significativamente reduzida nas paredes inferior, inferoseptal e ântero-septal, com resultados semelhantes em ambos os grupos.</title></caption>
<graphic xlink:href="2675-312X-abcimg-37-03-e20240053-gf02-pt.tif"/>
</fig>
</sec>
</sec>
<sec sec-type="discussion">
<title>Discussão</title>
<p>O envolvimento cardíaco da doença de Chagas apresenta-se mais comumente na forma de cardiomiopatia dilatada, como resultado de inflamação crônica com subsequente perda de cardiomiócitos. O estágio final da doença é caracterizado pela ruptura das fibras musculares e das estruturas neuronais com substituição por tecido fibrótico. Essa anomalia arquitetônica contribui para a disfunção eletrofisiológica e é um fator importante na propensão dos indivíduos chagásicos a apresentar arritmias ventriculares e insuficiência cardíaca,<sup><xref ref-type="bibr" rid="B18">18</xref>,<xref ref-type="bibr" rid="B20">20</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> sendo responsável por uma considerável taxa de morbidade e mortalidade.<sup><xref ref-type="bibr" rid="B15">15</xref></sup> O grau de disfunção ventricular também determina a gravidade da arritmia ventricular. Uma das principais causas de morte nesta população é a MSC, responsável por quase 55-60% das mortes. Pacientes com histórico de síncope, bradiarritmia grave e parada cardíaca têm maior probabilidade de desenvolver MSC.<sup><xref ref-type="bibr" rid="B18">18</xref>,<xref ref-type="bibr" rid="B21">21</xref>,<xref ref-type="bibr" rid="B22">22</xref></sup> As características clínicas podem ser divididas em três estágios: agudo, indeterminado e crônico. A doença de Chagas aguda geralmente persiste de 8 a 12 semanas e frequentemente permanece sem diagnóstico, já que a maioria dos pacientes é assintomática ou apresenta apenas sintomas leves e inespecíficos, como febre, cansaço, linfadenopatia, hepatomegalia e esplenomegalia. Sinais no local da infecção também podem ser observados, como o chagoma característico (abscesso cutâneo do T. cruzi) ou o sinal de Romaña (conjuntivite unilateral com inchaço indolor das pálpebras). Outros sistemas orgânicos menos frequentemente envolvidos incluem o trato gastrointestinal e o sistema nervoso. A doença fulminante comumente se apresenta com miocardite aguda, derrame pericárdico e trombose mural.<sup><xref ref-type="bibr" rid="B18">18</xref></sup> Na fase indeterminada, os pacientes são assintomáticos e apresentam FEVE preservada. Quase 20-40% dos pacientes com doença de Chagas aguda<sup><xref ref-type="bibr" rid="B23">23</xref></sup> desenvolvem doença crônica 20 a 30 anos depois, seja na forma de megaesôfago, megacólon ou doença cardíaca chagásica.<sup><xref ref-type="bibr" rid="B24">24</xref></sup> O envolvimento cardíaco é marcado por arritmias significativas (supraventriculares ou ventriculares) e aneurismas ventriculares.<sup><xref ref-type="bibr" rid="B25">25</xref></sup> Danos ao sistema de condução elétrica também são uma causa prevalente de bloqueio atrioventricular,<sup><xref ref-type="bibr" rid="B15">15</xref></sup> sendo o bloqueio de ramo direito (BRD) a anormalidade de condução intraventricular mais comum e frequentemente uma das primeiras manifestações da doença. A combinação de BRD e bloqueio fascicular anterior esquerdo é fortemente sugestiva de doença de Chagas<sup><xref ref-type="bibr" rid="B18">18</xref></sup> em grupos de alto risco. Também são relatadas formação de tromboembolismo pulmonar e sistêmico,<sup><xref ref-type="bibr" rid="B26">26</xref></sup> cicatrizes miocárdicas e anormalidades de motilidade parietal, mais comumente nas paredes apical e ínfero-lateral. As manifestações cardíacas constituem parte significativa da doença das taxas de morbidade e mortalidade da doença de Chagas, mas a deterioração clínica pode ter um curso insidioso, como visto na forma indeterminada. Pretendemos comparar a progressão da função ventricular esquerda por meio de múltiplos parâmetros ecocardiográficos nas formas indeterminada e crônica da doença de Chagas, através de uma série de casos. Dessa forma, sugerimos a possibilidade de utilização da DLG como valor incremental da FEVE na identificação precoce de alterações cardíacas. No grupo indeterminado, essas alterações de contratilidade segmentar são particularmente dignas de nota. Danos miocárdicos precoces, caracterizados por inflamação e fibrose, frequentemente localizados nas paredes inferior, inferoseptal e ântero-septal, foram documentados em pacientes com doença de Chagas indeterminada. Isto corrobora nossa observação de alterações de contratilidade nestes segmentos, evidenciando a necessidade de monitorização cardíaca vigilante mesmo em pacientes assintomáticos. A base fisiopatológica para estas alterações envolve uma resposta inflamatória contínua, com subsequente fibrose, que perturba a função miocárdica normal, particularmente nestas regiões vulneráveis.<sup><xref ref-type="bibr" rid="B15">15</xref>,<xref ref-type="bibr" rid="B21">21</xref></sup> Paralelamente, também foi realizada uma revisão da literatura sobre o tema. A análise das alterações miocárdicas do ventrículo esquerdo na cardiomiopatia chagásica, utilizando speckle tracking, foi estudada pela primeira vez em todo o espectro de frações de ejeção (de preservadas a reduzidas) por Lima et al.<sup><xref ref-type="bibr" rid="B27">27</xref></sup> O Speckle Tracking é uma ferramenta ecocardiográfica que permite o rastreamento quantitativo automatizado quadro a quadro das interações entre alterações acústicas e alterações miocárdicas regionais.<sup><xref ref-type="bibr" rid="B27">27</xref>,<xref ref-type="bibr" rid="B28">28</xref></sup> O estudo mostrou diminuição da deformação nas paredes inferior e posterior do coração com aumento paradoxal dos segmentos septais e anteriores ao longo da evolução da cardiomiopatia chagásica. Além disso, demonstrou velocidades longitudinais reduzidas na forma indeterminada.<sup><xref ref-type="bibr" rid="B27">27</xref></sup> Outro estudo transversal conseguiu demonstrar uma alteração anormal precoce na deformação longitudinal regional em pacientes com forma indeterminada localizada nos segmentos inferior, septal inferior e ínfero-lateral. Quando comparadas com a ressonância magnética cardíaca, essas alterações ocorreram antes da fibrose cardíaca.<sup><xref ref-type="bibr" rid="B29">29</xref></sup> O valor prognóstico dos biomarcadores e dos parâmetros de deformação foi estudado prospectivamente mais recentemente na mesma coorte que demonstrou uma associação independente de DLG VE, torção ventricular esquerda e níveis de peptídeo natriurético cerebral (PNC) com um resultado composto que consiste em mortalidade, internação hospitalar, insuficiência cardíaca transplante ou implantação de dispositivo em pacientes com doença de Chagas crônica.<sup><xref ref-type="bibr" rid="B30">30</xref></sup> Em nossa revisão, incluímos os dados do estudo sobre ecocardiografia speckle tracking na doença de Chagas atualmente presentes na literatura (<xref ref-type="table" rid="t10">Tabela 5</xref>). O conceito geral e resumo desta série de casos e revisão da literatura são apresentados na <xref ref-type="fig" rid="f6">figura central</xref>.</p>
<table-wrap id="t10">
<label>Tabela 5</label>
<caption><title>Dados sobre ecocardiografia speckle-tracking na doença de Chagas, atualmente presentes na literatura</title></caption>
<table frame="hsides" rules="groups">
<colgroup width="25%">
<col/>
<col/>
<col/>
<col/>
</colgroup>
<thead style="border-top: thin solid; border-bottom: thin solid; border-color: #000000">
<tr style="background-color:#BE8873;">
<th align="left" valign="middle">Autor(a)</th>
<th align="center" valign="middle">Tipo de estudo</th>
<th align="center" valign="middle">Participantes</th>
<th align="left" valign="middle">Parâmetros</th>
</tr>
</thead>
<tbody style="border-bottom: thin solid; border-color: #000000">
<tr>
<td align="left" valign="middle">Garcia-Alvaraez et al. (2011)<sup><xref ref-type="bibr" rid="B31">31</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">98</td>
<td align="left" valign="middle">DLG, deformação radial e circunferencial</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Barbosa et al. (2014)<sup><xref ref-type="bibr" rid="B32">32</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">78</td>
<td align="left" valign="middle">DLG, deformação radial e circunferencial</td>
</tr>
<tr>
<td align="left" valign="middle">Gomes et al. (2016)<sup><xref ref-type="bibr" rid="B33">33</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">126</td>
<td align="left" valign="middle">DLG, deformação radial e circunferencial</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Lima et al. (2016)<sup><xref ref-type="bibr" rid="B27">27</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">131</td>
<td align="left" valign="middle">DLG, deformação rotacional e de torção</td>
</tr>
<tr>
<td align="left" valign="middle">Lima et al. (2017)<sup><xref ref-type="bibr" rid="B34">34</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">42</td>
<td align="left" valign="middle">DLG, deformação rotacional e de torção</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Santos Jr. et al. (2019)<sup><xref ref-type="bibr" rid="B35">35</xref></sup></td>
<td align="center" valign="middle">Coorte prospectiva</td>
<td align="center" valign="middle">122</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr>
<td align="left" valign="middle">Echeverría et al. (2020)<sup><xref ref-type="bibr" rid="B36">36</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">273</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Cianciulli et al. (2021)<sup><xref ref-type="bibr" rid="B28">28</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">90</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr>
<td align="left" valign="middle">Romano et al. (2020)<sup><xref ref-type="bibr" rid="B29">29</xref></sup></td>
<td align="center" valign="middle">Transversal</td>
<td align="center" valign="middle">69</td>
<td align="left" valign="middle">DLG, deformação radial e circunferencial</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Echeverría et al. (2022)<sup><xref ref-type="bibr" rid="B17">17</xref></sup></td>
<td align="center" valign="middle">Coorte prospectiva</td>
<td align="center" valign="middle">177</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr>
<td align="left" valign="middle">Win et al. (2022)<sup><xref ref-type="bibr" rid="B15">15</xref></sup></td>
<td align="center" valign="middle">Coorte prospectiva</td>
<td align="center" valign="middle">139</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr style="background-color:#E3CABE;">
<td align="left" valign="middle">Hotta et al. (2022)<sup><xref ref-type="bibr" rid="B23">23</xref></sup></td>
<td align="center" valign="middle">Coorte prospectiva</td>
<td align="center" valign="middle">72</td>
<td align="left" valign="middle">DLG</td>
</tr>
<tr>
<td align="left" valign="middle">Mendes et al. (2023)<sup><xref ref-type="bibr" rid="B30">30</xref></sup></td>
<td align="center" valign="middle">Coorte prospectiva</td>
<td align="center" valign="middle">361</td>
<td align="left" valign="middle">DLG</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="TFN10"><p>DLG: deformação longitudinal global.</p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec sec-type="conclusions">
<title>Conclusão</title>
<p>Nosso estudo destaca a importância da detecção precoce e do manejo do envolvimento miocárdico na doença de Chagas. A adição da análise de DLG à ecocardiografia convencional produz um valor incremental potencial na detecção de alterações miocárdicas subclínicas antes da redução significativa na FEVE. As alterações de contratilidade segmentar observadas no grupo indeterminado enfatizam a importância do reconhecimento precoce do dano miocárdico. Imagens direcionadas e intervenções oportunas são cruciais para o manejo eficaz desses pacientes e para prevenir a progressão para a doença cardíaca sintomática. Quando comparada a pacientes com a variante crônica da doença de Chagas, a análise segmentar individual na forma indeterminada pode permitir o reconhecimento precoce de pacientes com risco de progressão para disfunção cardíaca clínica, conforme sugerido por esta série de casos e revisão sistemática da literatura, em consonância com os dados atuais disponíveis. Nossos achados são consistentes com a literatura existente, que destaca o envolvimento miocárdico subclínico na fase indeterminada da doença de Chagas, exigindo avaliação cardíaca proativa e estratégias de manejo adequadas para mitigar as complicações em longo prazo. No entanto, o impacto clínico e o significado destas técnicas mais recentes permanecem desconhecidos.</p>
</sec>
</body>
<back>
<fn-group>
<fn fn-type="financial-disclosure" id="fn4"><label>Fontes de Financiamento</label><p>O presente estudo não teve fontes de financiamento externas.</p></fn>
<fn fn-type="other" id="fn5"><label>Vinculação Acadêmica</label><p>Não há vinculação deste estudo a programas de pós-graduação.</p></fn>
<fn fn-type="other" id="fn6"><label>Aprovação Ética e Consentimento Informado</label><p>Este estudo foi aprovado pelo Comitê de Ética da Central de Diagnóstico e Pesquisa Clínica sob o número de protocolo 01.2023/579831. Todos os procedimentos envolvidos nesse estudo estão de acordo com a Declaração de Helsinki de 1975, atualizada em 2013. O consentimento informado foi obtido de todos os participantes incluídos no estudo.</p></fn>
</fn-group>
</back>
</sub-article>
</article>
