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<article xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mml="http://www.w3.org/1998/Math/MathML" dtd-version="1.0" specific-use="sps-1.1" article-type="case-report" xml:lang="en">
  <front>
    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Arq Bras Cardiol</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">XjcW6fb4RNWBXmWRgKP3yNh</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2015000200013</article-id>
      <article-id pub-id-type="other">00013</article-id>
      <article-id pub-id-type="doi">10.5935/abc.20140218</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Clinicoradiological Session</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Case 2/2015 A 33-Year-Old Woman with Double Right Ventricular Chamber and
               Ventricular Septal Defect</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Atik</surname>
            <given-names>Edmar</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="corresp" rid="c01"/>
        </contrib>
        <aff id="aff01">
          <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
          <institution content-type="orgdiv1">Faculdade de Medicina</institution>
          <institution content-type="orgdiv2">Instituto do Cora&#231;&#227;o</institution>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country>Brazil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o, Faculdade de Medicina,
                  Universidade de S&#227;o Paulo &#8211; USP, S&#227;o Paulo, SP - Brazil</institution>
          <institution content-type="normalized">Universidade de S&#227;o Paulo</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c01"><bold>Mailling Address: Edmar Atik,</bold> Rua Dona Adma Jafet, 74,
               conj. 73, Bela Vista. Postal Code 01308-050. S&#227;o Paulo, SP &#8211; Brazil. E-mail:
                  <email>eatik@cardiol.br</email>; <email>conatik@incor.usp.br</email></corresp>
      </author-notes>
      <pub-date pub-type="epub-ppub">
        <month>02</month>
        <year>2015</year>
      </pub-date>
      <volume>104</volume>
      <issue>2</issue>
      <fpage>e12</fpage>
      <lpage>e14</lpage>
      <history>
        <date date-type="received">
          <day>23</day>
          <month>07</month>
          <year>2014</year>
        </date>
        <date date-type="rev-recd">
          <day>31</day>
          <month>07</month>
          <year>2014</year>
        </date>
        <date date-type="accepted">
          <day>31</day>
          <month>07</month>
          <year>2014</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/3.0/">
          <license-p>This is an Open Access article distributed under the terms of the Creative
                  Commons Attribution Non-Commercial License which permits unrestricted
                  non-commercial use, distribution, and reproduction in any medium, provided the
                  original work is properly cited.</license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="en">
        <kwd>Double chambered right ventricle</kwd>
        <kwd>right ventricle inflow tract stenosis</kwd>
        <kwd>ventricular septal defect</kwd>
        <kwd>hipertrophy of right ventricle</kwd>
      </kwd-group>
      <counts>
        <fig-count count="4"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="2"/>
        <page-count count="3"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <p><bold>Clinical data:</bold> non-progressive shortness of breath on moderate exertion for 1
         year. A heart murmur had been heard at one month of age, and the patient had been followed
         up irregularly ever since. She did not report cyanosis and had recently been prescribed
         with hydrochlorothiazide. Laboratory tests showed H = 4,700,000/mm<sup>3</sup>; Hct = 41%;
         Hg = 13.4 g/dL.</p>
    <p><bold>Physical examination:</bold> normal breathing, acyanotic, normal pulses. Weight: 62
         kg; height: 163 cm; blood pressure: 110/60 mmHg; heart rate: 78 bpm; oxygen saturation:
         97%; aorta not palpable on the suprasternal notch.</p>
    <p>The apical impulse was not palpable in the precordium, and there were no systolic impulses
         on the left sternal border. Normal heart sounds; grade 3/4 course systolic murmur on the
         mid-left sternal border accompanied by thrill. The liver was not palpable.</p>
    <sec>
      <title>Laboratory tests</title>
      <p><bold>Electrocardiogram</bold> showed normal sinus rhythm and signs of right ventricular
            (RV) overload. Low-voltage QRS complex with qR morphology in V1, RS in V6 with final
            conduction disturbance through the right bundle branch. QRSA: -70&#186;, TA: + 30&#186;.</p>
      <p><bold>Chest radiograph</bold> showed normal cardiac silhouette (cardiothoracic ratio of
            0.46). The pulmonary vascular network was normal and the arch of the pulmonary artery
            was concave (<xref ref-type="fig" rid="f01">Figure 1</xref>).</p>
      <fig id="f01">
        <label>Figure 1</label>
        <caption>
          <title>Chest radiograph showing normal cardiac silhouette, with a round shape
                  resulting from myocardial hypertrophy due to an obstructive lesion on the right
                  side.</title>
        </caption>
        <graphic xlink:href="1678-4170-abc-104-02-0e12-40218-gf01.jpg"/></fig>
      <p><bold>Echocardiogram</bold> (<xref ref-type="fig" rid="f02">Figure 2</xref>) showed
            right ventricular inflow tract stenosis causing an intraventricular gradient of 80 mmHg,
            with a 13-mm diameter ventricular septal defect partially occluded by the tricuspid
            valve, thus resulting in an effective 4.7&#8209;mm orifice. There was RV hypertrophy with
            mildly enlarged right cardiac chambers. Gradient between ventricles was 82 mmHg. There
            was a small aneurysm formation in the ventricular septum. Measurements were as follows:
            left ventricle (LV) = 45 mm; left atrium (LA) = 32; Ao = 26; septum = posterior wall = 7
            mm. LV ejection fraction = 66%. There was a 3-mm foramen ovale with bidirectional
            predominantly left&#8209;to&#8209;right shunt. RV systolic pressure = 110 mmHg.</p>
      <fig id="f02">
        <label>Figure 2</label>
        <caption>
          <title>(A) 4-chamber apical view echocardiogram shows ventricular septal defect with
                  septal aneurysm (arrow); (B and C) short-axis cross-sectional view showing right
                  ventricular inflow tract stenosis (arrows, in colors). (D) Angiography showing
                  septal aneurysm (arrow) and (E) right ventricular inflow tract stenosis (arrow)
                  with marked hypertrophy.</title>
        </caption>
        <graphic xlink:href="1678-4170-abc-104-02-0e12-40218-gf02.jpg"/></fig>
      <p><bold>Cardiac catheterization</bold> (<xref ref-type="fig" rid="f02">Figure 2</xref>)
            Pressure values were: RV inflow tract = 98/13; RV outflow tract = 25/7; PT = 20/7-12; LV
            = 124/11; Ao = 126/64; PC = 11 mmHg.</p>
      <p><bold>Clinical diagnosis:</bold> Severe RV inflow tract stenosis with perimembranous
            ventricular septal defect of little impact, with no hypoxemia and/or heart failure, in
            natural course.</p>
      <p><bold>Clinical reasoning:</bold> The clinical elements of long-standing right
            obstructive congenital heart defects without hypoxemia present as shortness of breath
            and are not accompanied by hematocrit elevation. For this reason, with preserved cardiac
            output, their outcome is favorable thanks to compensatory myocardial hypertrophy. The
            normal heart sounds suggest normal arterial position, and the preserved pulmonary flow
            results from an adequate compensatory mechanism. The severe systolic murmur in the
            mid-left sternal border suggests the presence of an obstructive lesion in the RV inflow
            tract and differentiates from the murmur of the ventricular septal defect for being
            coarser and stronger. Ventricular septal defects of little impact do not result in any
            functional disturbance, and their auscultatory manifestation mingles with that of the
            obstructive defect. RV systolic overload on the electrocardiogram suggests the diagnosis
            of an obstructive lesion on the right. Chest radiograph showing normal cardiac
            silhouette is consistent with good RV function, and the normal pulmonary vascular
            network results from the maintained antegrade flow.</p>
      <p><bold>Differential diagnosis:</bold> Heart diseases with RV outflow tract obstruction
            may have a similar presentation, except for the systolic murmur, which is more intense
            in the upper left sternal border, irradiating to the neck vessels, albeit mildly.</p>
      <p><bold>Management:</bold> Because of the long-standing systolic impact with severe
            hypertrophy and nearly systemic RV pressures, indication of operation becomes mandatory,
            aiming at relieving the chamber obstruction, which would imply a greater possibility of
            development of myocardial fibrosis, heart failure, arrhythmias and earlier death.</p>
      <p><bold>Commentaries:</bold> Obstructive congenital heart defects usually manifest early
            in life by means of a heart murmur. Cardiac compensation with maintained antegrade flow
            is achieved by myocardial hypertrophy. The consequences of this phenomenon are directly
            proportional to the degree of obstruction. In the present case, this obstruction, which
            was more intense in adulthood and whose manifestation of symptoms had been more recent,
            progressed throughout time, which permitted a good outcome during this period. Hence,
            the patient had a favorable course up to the fourth decade of life. Most of these
            patients are treated in childhood and very uncommonly in adulthood. These defects result
            from an impaired growth of the trabecular myocardium during the early fetal formation,
            and the non-uniformity in its position, closer to the tricuspid or pulmonary valve,
            which causes the ventricle to divide into two parts &#8211; a proximal and a distal part. They
            are frequently associated with ventricular septal defects (80% of cases)<xref ref-type="bibr" rid="B01">1</xref><sup>,</sup><xref ref-type="bibr" rid="B02">2</xref>. Even when their impact is minor, these obstructive anomalies should be
            treated earlier to prevent an unfavorable outcome in relation to the development of
            myocardial fibrosis, arrhythmias and heart failure.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <title>References</title>
      <ref id="B01">
        <label>1</label>
        <mixed-citation>L&#243;pez-Fern&#225;ndez S, Molina-Lerma MJ, Garc&#237;a-Orta R, Medina-Benitez A.
               Double-chambered right ventricle in adults: an 'uncommon' entity, new ways of
               imaging. Eur Heart J. 2013;34(11):801.</mixed-citation>
        <element-citation publication-type="journal">
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            <name>
              <surname>L&#243;pez-Fern&#225;ndez</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Molina-Lerma</surname>
              <given-names>MJ</given-names>
            </name>
            <name>
              <surname>Garc&#237;a-Orta</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Medina-Benitez</surname>
              <given-names>A</given-names>
            </name>
          </person-group>
          <article-title>Double-chambered right ventricle in adults: an 'uncommon' entity, new
                  ways of imaging</article-title>
          <source>Eur Heart J</source>
          <year>2013</year>
          <volume>34</volume>
          <issue>11</issue>
          <fpage>801</fpage>
          <lpage>801</lpage>
        </element-citation>
      </ref>
      <ref id="B02">
        <label>2</label>
        <mixed-citation>Lee WJ, Song BG, Kang GH, Park YH, Chun WJ, Oh JH. A case of
               asymptomatic isolated double-chambered right ventricle in an adult man. J Clin
               Ultrasound. 2013;41(9):579-81.</mixed-citation>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Lee</surname>
              <given-names>WJ</given-names>
            </name>
            <name>
              <surname>Song</surname>
              <given-names>BG</given-names>
            </name>
            <name>
              <surname>Kang</surname>
              <given-names>GH</given-names>
            </name>
            <name>
              <surname>Park</surname>
              <given-names>YH</given-names>
            </name>
            <name>
              <surname>Chun</surname>
              <given-names>WJ</given-names>
            </name>
            <name>
              <surname>Oh</surname>
              <given-names>JH</given-names>
            </name>
          </person-group>
          <article-title>A case of asymptomatic isolated double-chambered right ventricle in an
                  adult man</article-title>
          <source>J Clin Ultrasound</source>
          <year>2013</year>
          <volume>41</volume>
          <issue>9</issue>
          <fpage>579</fpage>
          <lpage>581</lpage>
        </element-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="SA1" xml:lang="pt">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Correla&#231;&#227;o Cl&#237;nico-radiogr&#225;fica</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Caso 2/2015 - Mulher de 33 anos com Dupla C&#226;mara Ventricular Direita e
               Comunica&#231;&#227;o Interventricular</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Atik</surname>
            <given-names>Edmar</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="corresp" rid="c02"/>
        </contrib>
        <aff id="aff0">
          <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
          <institution content-type="orgdiv1">Faculdade de Medicina</institution>
          <institution content-type="orgdiv2">Instituto do Cora&#231;&#227;o</institution>
          <addr-line>
            <named-content content-type="city">S&#227;o Paulo</named-content>
            <named-content content-type="state">SP</named-content>
          </addr-line>
          <country>Brasil</country>
          <institution content-type="original">Instituto do Cora&#231;&#227;o, Faculdade de Medicina,
                  Universidade de S&#227;o Paulo &#8211; USP, S&#227;o Paulo, SP - Brasil</institution>
          <institution content-type="normalized">Universidade de S&#227;o Paulo</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c02"><bold>Correspond&#234;ncia: Edmar Atik,</bold> Rua Dona Adma Jafet, 74,
               conj. 73, Bela Vista. CEP 01308-050. S&#227;o Paulo, SP &#8211; Brasil. E-mail:
                  <email>eatik@cardiol.br</email>; <email>conatik@incor.usp.br</email></corresp>
      </author-notes>
      <kwd-group xml:lang="pt">
        <kwd>Dupla c&#226;mara de ventr&#237;culo direito</kwd>
        <kwd>estenose de via de entrada de ventr&#237;culo direito</kwd>
        <kwd>comunica&#231;&#227;o interventricular</kwd>
        <kwd>hipertrofia de ventr&#237;culo direito</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p><bold>Dados cl&#237;nicos:</bold> cansa&#231;o aos m&#233;dios esfor&#231;os h&#225; 1 ano, sem progress&#227;o. Sopro
            card&#237;aco havia sido auscultado com 1 m&#234;s de vida e, desde ent&#227;o, estava em
            acompanhamento irregular. N&#227;o relatava cianose e, recentemente, foi medicada com
            hidroclorotiazida. Exames laboratoriais mostraram H = 4.700.000/mm<sup>3</sup>; Hct =
            41%; Hg = 13,4 g/dL.</p>
      <p><bold>Exame f&#237;sico:</bold> eupneica, acian&#243;tica, pulsos normais. Peso: 62 kg; altura:
            163 cm; press&#227;o arterial: 110/60 mmHg; frequ&#234;ncia card&#237;aca: 78 bpm; satura&#231;&#227;o de
            oxig&#234;nio: 97%; aorta n&#227;o palpada na f&#250;rcula.</p>
      <p>No prec&#243;rdio, <italic>ictus cordis</italic> n&#227;o palpado e aus&#234;ncia de impuls&#245;es
            sist&#243;licas na B EE. Bulhas card&#237;acas normofon&#233;ticas; sopro sist&#243;lico, +++/4, rude, borda
            esternal esquerda m&#233;dia, acompanhado de fr&#234;mito. O f&#237;gado n&#227;o era palpado.</p>
      <sec>
        <title>Exames complementares</title>
        <p><bold>Eletrocardiograma</bold> mostrava ritmo sinusal e sinais de sobrecarga de
               ventr&#237;culo direito (VD). O complexo QRS era de baixa voltagem com morfologia qr em
               V1, RS em V6 com dist&#250;rbio final de condu&#231;&#227;o pelo ramo direito. AQRS: -70&#186;, AT: +
               30&#186;.</p>
        <p><bold>Radiografia</bold> de t&#243;rax mostrava &#225;rea card&#237;aca normal (&#237;ndice
               cardiotor&#225;cico de 0,46). A trama vascular pulmonar era normal e o arco m&#233;dio,
               escavado (<xref ref-type="fig" rid="f03">Figura 1</xref>).</p>
        <fig id="f03">
          <label>Figura 1</label>
          <caption>
            <title>Radiografia de t&#243;rax mostra &#225;rea card&#237;aca normal, com forma arredondada
                     decorrente da hipertrofia mioc&#225;rdica, por les&#227;o obstrutiva &#224; direita.</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-104-02-0e12-40218-gf01-pt.jpg"/></fig>
        <p><bold>Ecocardiograma</bold> (<xref ref-type="fig" rid="f04">Figura 2</xref>) mostrou
               estenose na via de entrada de ventr&#237;culo direito causando gradiente intraventricular
               de 80 mmHg, com comunica&#231;&#227;o interventricular de 13 mm de di&#226;metro, parcialmente
               oclu&#237;da pela valva tric&#250;spide, originando orif&#237;cio efetivo de 4,7 mm. Havia
               hipertrofia de VD com discreto aumento das cavidades card&#237;acas direitas. Gradiente
               entre os ventr&#237;culos era de 82 mmHg. Havia forma&#231;&#227;o de pequeno aneurisma no septo
               ventricular. As dimens&#245;es eram: ventr&#237;culo esquerdo (VE) = 45 mm; &#225;trio esquerdo (AE)
               = 32; Ao = 26; septo = parede posterior = 7 mm. Fra&#231;&#227;o de eje&#231;&#227;o do VE = 66%. Havia
               forame oval de 3 mm com <italic>shunt</italic> bidirecional, preferentemente para a
               direita. Press&#227;o sist&#243;lica do VD = 110 mmHg.</p>
        <fig id="f04">
          <label>Figura 2</label>
          <caption>
            <title>(A) Ecocardiograma em corte apical de 4 c&#226;maras mostra comunica&#231;&#227;o
                     interventricular com aneurisma septal (seta); (B e C) em corte transversal eixo
                     curto, observa-se a estenose de via de entrada de ventr&#237;culo direito (setas, em
                     cores). (D) Angiografia salienta o aneurisma septal (seta) e (E) a estenose de
                     via de entrada de ventr&#237;culo direito (seta) com acentuada hipertrofia.</title>
          </caption>
          <graphic xlink:href="1678-4170-abc-104-02-0e12-40218-gf02-pt.jpg"/></fig>
        <p><bold>Cateterismo card&#237;aco</bold> (<xref ref-type="fig" rid="f02">Figura 2</xref>) As
               press&#245;es eram: VD via de entrada = 98/13; VD via de sa&#237;da = 25/7; TP = 20/7-12; VE =
               124/11; Ao = 126/64; CP = 11 mmHg.</p>
        <p><bold>Diagn&#243;stico cl&#237;nico:</bold> Estenose acentuada de via de entrada de VD com
               comunica&#231;&#227;o interventricular perimembranosa de pequena repercuss&#227;o, sem hipoxemia
               e/ou insufici&#234;ncia card&#237;aca, em evolu&#231;&#227;o natural.</p>
        <p><bold>Racioc&#237;nio cl&#237;nico:</bold> os elementos cl&#237;nicos de cardiopatia cong&#234;nita
               obstrutiva direita e sem hipoxemia, de longa data, expressam-se por cansa&#231;o e n&#227;o
               mostram eleva&#231;&#227;o do hemat&#243;crito. Por isso, com manuten&#231;&#227;o do d&#233;bito card&#237;aco,
               apresentam boa evolu&#231;&#227;o &#224; custa de hipertrofia mioc&#225;rdica compensadora. As bulhas
               normofon&#233;ticas orientam &#224; normoposi&#231;&#227;o arterial, e o fluxo pulmonar conservado
               decorre de mecanismo compensador adequado. O sopro sist&#243;lico intenso no meio da borda
               esternal esquerda indica a presen&#231;a de les&#227;o obstrutiva na via de entrada de VD e se
               diferencia do sopro da comunica&#231;&#227;o interventricular, por se apresentar com timbre
               mais rude e com intensidade maior. Comunica&#231;&#227;o interventricular de pequena
               repercuss&#227;o n&#227;o acarreta qualquer dist&#250;rbio funcional, e sua manifesta&#231;&#227;o auditiva se
               mistura &#224; do defeito obstrutivo. Sobrecarga sist&#243;lica de VD no eletrocardiograma
               orienta o diagn&#243;stico da les&#227;o obstrutiva &#224; direita. Radiografia de t&#243;rax com &#225;rea
               card&#237;aca normal salienta a boa funcionalidade do VD, e a trama vascular pulmonar
               normal decorre da manuten&#231;&#227;o do fluxo anter&#243;grado.</p>
        <p><bold>Diagn&#243;stico diferencial:</bold> cardiopatias com obstru&#231;&#227;o na via de sa&#237;da do
               VD podem se apresentar de maneira semelhante, exceto pelo sopro sist&#243;lico, que se
               acentua mais na borda esternal esquerda alta e com irradia&#231;&#227;o aos vasos do pesco&#231;o,
               embora tenuemente.</p>
        <p><bold>Conduta:</bold> em face da repercuss&#227;o sist&#243;lica de longa data com hipertrofia
               acentuada e com press&#245;es quase sist&#234;micas do VD, torna-se imperiosa a indica&#231;&#227;o
               operat&#243;ria, visando ao al&#237;vio da obstru&#231;&#227;o cavit&#225;ria, que suscita maior possibilidade
               para instala&#231;&#227;o de fibrose mioc&#225;rdica, insufici&#234;ncia card&#237;aca, arritmias e morte mais
               precoce.</p>
        <p><bold>Coment&#225;rios:</bold> as anomalias cong&#234;nitas obstrutivas geralmente se
               manifestam precocemente na vida por meio de ausculta de sopro card&#237;aco. A compensa&#231;&#227;o
               card&#237;aca com manuten&#231;&#227;o do fluxo anter&#243;grado &#233; obtida pela hipertrofia mioc&#225;rdica. A
               repercuss&#227;o desse fen&#244;meno &#233; diretamente proporcional ao grau da obstru&#231;&#227;o. No
               presente caso, possivelmente essa obstru&#231;&#227;o, acentuada na idade adulta e com
               manifesta&#231;&#227;o sintom&#225;tica mais recente, foi se acentuando progressivamente ao longo do
               tempo, o que permitiu boa evolu&#231;&#227;o nesse per&#237;odo. Da&#237; o paciente apresentar evolu&#231;&#227;o
               favor&#225;vel at&#233; a quarta d&#233;cada da vida. A maioria desses pacientes &#233; tratada na
               inf&#226;ncia e muito raramente na fase adulta. A decorr&#234;ncia &#233; a obstru&#231;&#227;o do crescimento
               de mioc&#225;rdio trabecular durante a forma&#231;&#227;o precoce fetal, e n&#227;o h&#225; uniformidade em
               sua posi&#231;&#227;o, mais pr&#243;xima da valva tric&#250;spide ou da pulmonar, fato que divide o
               ventr&#237;culo em duas partes, proximal e distal. Associa-se frequentemente (80% dos
               casos), em especial &#224; comunica&#231;&#227;o interventricular<xref ref-type="bibr" rid="B01">1</xref><sup>,</sup><xref ref-type="bibr" rid="B02">2</xref>. Essa anomalia
               obstrutiva, mesmo com menor repercuss&#227;o, deve ser tratada mais precocemente, para se
               evitar evolu&#231;&#227;o desfavor&#225;vel em rela&#231;&#227;o ao surgimento de fibrose mioc&#225;rdica,
               arritmias e insufici&#234;ncia card&#237;aca.</p>
      </sec>
    </body>
  </sub-article>
</article>
