Electric Countershock – ABC CARDIOL

ABC

Editorial

Rhythm Control Interventions in Patients with Atrial Fibrillation – Insights on Preprocedural Anticoagulation and Utility of Left Atrial Imaging

The most common sustained arrhythmia in clinical practice is atrial fibrillation (AF),^, affecting 2-4% of the adult population worldwide. It is even more frequent with aging, with almost 10% prevalence in individuals older than 80. Current estimates state that one in every three adults aged 55 years will develop AF during their lifetime, leading to substantial healthcare and economic burden. Clinical issues relate primarily to thromboembolic events (TE) and arrhythmic symptoms, both central targets while managing patients with AF.^,

Overall, atrial fibrillation confers a 2-5-fold escalated risk of TE, which is not evenly distributed, depending on unique modifiers. Important risk factors abridged in the CHA₂DS₂-VASc score – Congestive heart failure, Hypertension, Age ≥75 years, Diabetes, Stroke/TIA, Vascular disease, Age 65-74 years, Sex (female) – may predict stroke risk, consistently mitigated in almost 70% by proper anticoagulation. Vitamin K antagonists (VKAs) were the only oral anticoagulants available for over half a century. From 2009 to 2013, pivotal randomized controlled trials acquainted the scientific community with the new/direct oral anticoagulants (DOACs).^– These drugs not only held similar efficacy to VKA in preventing thromboembolic events but also had a better safety profile against major bleeding – notably intracranial hemorrhage – and a more predictable pharmacokinetic and pharmacodynamic profile, ruling out the need for routine laboratory monitoring. However, the applicability of DOACs in off-label backgrounds, including stroke prevention during rhythm control interventions, remained unclear for many years.

[…]

Read Full Article

ABC

Original Article

Defibrillation Threshold Testing and Long-term Follow-up in Chagas Disease

Marco Paulo Cunha Campos et al. Luiz Fernando Gouveia Bernardes João Paulo Chaves de Melo Lucas Corsino dos Santos … Cristiano Honório Ribeiro Teixeira Maria Licia Ribeiro Cury Pavão Elerson Arfelli Adilson Scorzoni Filho Anis Rassi Jr José A. Marin-Neto André Schmidt

Abstract

Background

Sudden cardiac death is the most common cause of death in chronic Chagas cardiomyopathy (CCC). Because most CCC patients who are candidates for implantable cardioverter-defibrillators (ICD) meet criteria for high defibrillation threshold values, a defibrillator threshold test (DTT) is suggested.

Objectives

We investigated the use of DTT in CCC patients, focusing on deaths related to ICD and arrhythmic events, as well as treatment during long-term follow-up.

Methods

We retrospectively evaluated 133 CCC patients who received an ICD mainly for secondary prevention. Demographic, clinical, laboratory data, Rassi score, and DTT data were collected, with p < 0.05 considered significant.

Results

The mean patient age was 61 (SD, 13) years and 72% were men. The baseline left ventricular ejection fraction was 40 (SD, 15%) and the mean Rassi score was 10 (SD, 4). No deaths occurred during DTT and no ICD failures were documented. There was a relationship between higher baseline Rassi scores and higher DTT scores (ANOVA = 0.007). The mean time to first shock was 474 (SD, 628) days, although shock was only necessary for 28 (35%) patients with ventricular tachycardia, since most cases resolved spontaneously or through antitachycardia pacing. After a mean clinical follow-up of 1728 (SD, 1189) days, 43 deaths occurred, mainly related to progressive heart failure and sepsis.

Conclusions

A routine DTT may not be necessary for CCC patients who receive an ICD for secondary prevention. High DTT values seem to be unusual and may be related to high Rassi scores.

Read Full Article

ABC

Original Article

Left Atrial Thrombus and Dense Spontaneous Contrast in Direct Oral Anticoagulant Therapy of Atrial Fibrillation: Insights from a Reference Center

Thiago Marques et al. Francisco Darrieux Fábio Gouvêa Leandro Garambone … Ana Paula Lindoso João Lage Luciana Sacilotto Ana Lúcia Coimbra Martina Pinheiro Natália Olivetti Sissy Lara Carina Hardy Guilherme Athayde Denise Hachul Cristiano Pisani Tan Chen Wu Maurício Scanavacca

Abstract

Background

In the treatment of atrial fibrillation (AF), the most frequently sustained arrhythmia, with catheter ablation (CA) or electrical cardioversion (ECV), the periprocedural period is one of the most critical phases. Currently, the use of new direct action oral anticoagulants (DOAC) is increasingly frequent; however, in the real world, there are still few data on studies on the thrombus incidence in the left atrium (TrLA) or dense spontaneous contrast (DSC) on transesophageal echocardiogram (TEE).

Objective

To evaluate the prevalence of events and association with risk factors in patients using DOACs. Primary objective: to analyze the prevalence of thrombus in the LA by TEE in patients using DOAC undergoing ECV/CA. Second, evaluate the association of comorbidities with the presence of thrombi and DSC.

Methods

Retrospective cohort, single-center study with patients followed at the Arrhythmia Outpatient Unit (InCor-HCFMUSP). Patients indicated for procedures and using DOACs were selected, and their clinical/echocardiographic data were analyzed. A significance level of 5% was considered.

Results

354 patients were included, a total of 400 procedures, from March 2012-March 2018. Thrombus in the LA was found in 11 patients (2.8%), associated with advanced age (p=0.007) and higher CHA2DS2-VASc (p<0.001) score. DSC in the LA before TEE was found in 29 patients (7.3%), with lower LVEF (p<0.038) and greater LA dimension (p<0.0001).

Conclusion

The incidence of LA thrombus and DSC in patients using DOC in the context of AF ECV/CA, although small, is not negligible. Patients with higher CHA2DS2-VASc scores, especially older and with larger LA diameter, are more prone to these echocardiographic findings.

Read Full Article

ABCIC

Case Report

Arrhythmogenic Right Ventricular Dysplasia: Case Report and Literature Review

Gustavo Ney de Morais Gouveia et al. Carlos José Mota de Lima Benício Kerlly Barbosa Gonçalves Cezário Antônio Martins Gomes … Nelson Lopes Evangelista Ana Carolina Brito de Alcantara

[…]

Read Full Article

ABC

Image

One Patient, Two Cardiomyopathies

Christopher Strong et al. Pedro Freitas António Ferreira Gustavo Rodrigues Miguel Mendes

A 50-year-old male patient, with history of well-controlled hypertension and no known personal or family history of cardiac disease, presented with chest pain followed by syncope during strenuous physical activity. The electrocardiogram showed sustained monomorphic ventricular tachycardia. Electrical cardioversion was performed, with conversion to sinus rhythm with Q waves on leads V2-5 and III-aVF (). Transthoracic echocardiography (TTE) showed asymmetric left ventricular (LV) hypertrophy, preserved ejection fraction (EF) with apical akinesia, and hypertrabeculated right ventricle (RV). Coronary angiography showed no significant lesions. Cardiac MRI confirmed the TTE findings, showing a maximum LV wall thickness of 17 mm at the interventricular septum (Figure S1 — supplementary material), apical LV aneurysm and abnormal insertion of papillary muscles. The right side was remarkable for hypertrabeculated and hypokinetic free and inferior walls, and mildly dilated RV with reduced EF (33%). Besides having transmural delayed enhancement (DE) on the LV apex, there was also nodular DE on the LV/RV junction and on the free and inferior basal walls of the RV (; –; Figure S2 of supplementary material). Genetic analysis found a heterozygous mutation on the PKP2 gene (p.Thr50Serfs*61), a pathogenic variant associated with arrhythmogenic RV cardiomyopathy. However, no known mutation on genes related to hypertrophic cardiomyopathy (HCM) were found on a panel of 204 genes, 118 related to HCM. No association has been firmly made between mutations on the PKP2 gene and HCM. The overlap between genetics and cardiomyopathy phenotypes is a well-known phenomenon. We hypothesize that this patient either had an additional unknown HCM gene mutation or, less likely, a phenotypic expression of two different cardiomyopathies in the context a PKP2 gene mutation.

[…]

Read Full Article

ABC

Original Article

Predictors of Atrial Fibrillation Recurrence in Hyperthyroid and Euthyroid Patients

Muhammet Gürdoğan et al. Hasan Ari Erhan Tenekecioğlu Selma Ari … Tahsin Bozat Vedat Koca Mehmet Melek

Background:

Atrial fibrillation (AF) is the most common arrhythmia in adults, and is encountered in 10-15% of the patients with hyperthyroidism. Unless euthyroidism is restored, pharmacological or electrical cardioversion is controversial in patients with AF who remain hyperthyroid.

Objective:

The aim of this study was to assess the efficacy of electrical cardioversion and predictors of AF recurrence in hyperthyroid and euthyroid patients.

Methods:

The study included 33 hyperthyroid (21 males) and 48 euthyroid (17 males) patients with persistent AF. The patients were sedated with intravenous midazolam before undergoing electrical cardioversion delivered by synchronized biphasic shocks. Rates of AF recurrence were recorded.

Results:

Mean follow-up was 23.63 ± 3.74 months in the hyperthyroid group and 22.78 ± 3.15 months in the euthyroid group (p = 0.51). AF recurred in 14 (43.8%) and 21 (44.7%) patients in each group, respectively (p = 0.93). Multivariate regression analysis in each group showed that AF duration was the only predictor of AF recurrence, with odds ratios of 1.38 (95% confidence interval [CI] = 1.05 – 1.82, p = 0.02) in the hyperthyroid group and 1.42 (95% CI = 1.05 – 1.91, p= 0.02) in the euthyroid group.

Conclusion:

Rates of long-term AF recurrence were similar in successfully cardioverted hyperthyroid and euthyroid patients. The only predictor of AF recurrence in both groups was AF duration.

Read Full Article

ABC

Original Article

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

Rodrigo Tavares Silva et al. Martino Martinelli Filho Giselle de Lima Peixoto José Jayme Galvão de Lima … Sérgio Freitas de Siqueira Roberto Costa Luís Henrique Wolff Gowdak Flávio Jota de Paula Roberto Kalil Filho José Antônio Franchini Ramires

Abstract

Background:

The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.

Objective:

We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR).

Methods:

A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.

Results:

During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041).

Conclusions:

In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

Read Full Article

ABC

Case Report

Prolonged Cardiopulmonary Arrest Treated Successfully in the São Paulo's Subway

Renan Gianotto-Oliveira et al. Maria Helena Favarato Maria Margarita Gonzalez Thiago Liguori … Sergio Timerman Roberto Kalil Filho

Introduction

In Brazil, circulatory diseases, including CPA (Cardiopulmonary Arrests), were the leading cause of death in 2010. Estimates are that, in Brazil, around 220,000 CPAs happen every year, including ventricular fibrillation, 180,000 in pre-hospital environment and 40,000 in-hospital.

Recent observational studies of victims of CPA in extra-hospital environment revealed that only CCC (Continuous Chest Compressions) – hands-only CPR – were equivalent or higher than conventional CPR (Cardiopulmonary Resuscitation) (using a 30:2 ratio of compressions/ventilations) in adult patients, mainly with regard to neurological benefits ^– .

[…]

Read Full Article