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  <front>
    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Arq Bras Cardiol</journal-id>
      <journal-id journal-id-type="publisher-id">abc</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 - SBC</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id specific-use="scielo-v3" pub-id-type="publisher-id">NgkJ4brVnywV4c5hcbH857s</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2021000900142</article-id>
      <article-id pub-id-type="publisher-id">abc.20201012</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20201012</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Carta Cient&#237;fica</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Hipoplasia do Cora&#231;&#227;o Esquerdo em Evolu&#231;&#227;o at&#233; 21 Anos, Ap&#243;s Opera&#231;&#227;o Cavopulmonar Total Realizada com 5 Anos de Idade</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-7773-4174</contrib-id>
          <name>
            <surname>Atik</surname>
            <given-names>Edmar</given-names>
          </name>
          <xref ref-type="aff" rid="aff1"/>
        </contrib>
      </contrib-group>
      <aff id="aff1">
        <institution content-type="orgdiv2">Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas</institution>
        <institution content-type="orgdiv1">Faculdade de Medicina</institution>
        <institution content-type="orgname">Universidade de S&#227;o Paulo</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 country="BR">Brasil</country>
        <institution content-type="original">Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP - Brasil</institution>
      </aff>
      <author-notes>
        <corresp id="c01"> Correspond&#234;ncia: Edmar Atik &#8226; Rua Dona Adma Jafet 74 cj 73. CEP 01308-050, S&#227;o Paulo, SP &#8211; Brasil E-mail: <email>edmar.atik@incor.usp.br</email> </corresp>
        <fn fn-type="con">
          <p>Contribui&#231;&#227;o dos autores</p>
          <p>Concep&#231;&#227;o e desenho da pesquisa, Obten&#231;&#227;o de dados, An&#225;lise e interpreta&#231;&#227;o dos dados, Reda&#231;&#227;o do manuscrito e Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do intelectual importante: Atik E.</p>
        </fn>
        <fn fn-type="conflict">
          <p>Potencial conflito de interesse</p>
          <p>N&#227;o h&#225; conflito com o presente artigo</p>
        </fn>
      </author-notes>
      <pub-date date-type="pub" publication-format="electronic">
        <day>26</day>
        <month>07</month>
        <year>2021</year>
      </pub-date>
      <pub-date publication-format="electronic" date-type="collection">
        <month>07</month>
        <year>2021</year>
      </pub-date>
      <volume>117</volume>
      <issue>1</issue>
      <fpage>142</fpage>
      <lpage>145</lpage>
      <history>
        <date date-type="received">
          <day>11</day>
          <month>09</month>
          <year>2020</year>
        </date>
        <date date-type="rev-recd">
          <day>14</day>
          <month>10</month>
          <year>2020</year>
        </date>
        <date date-type="accepted">
          <day>14</day>
          <month>10</month>
          <year>2020</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, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. </license-p>
        </license>
      </permissions>
      <kwd-group xml:lang="pt">
        <kwd>S&#237;ndrome do Cora&#231;&#227;o Esquerdo Hipopl&#225;sico</kwd>
        <kwd>T&#233;cnica de Fontan</kwd>
        <kwd>Procedimentos Cir&#250;rgicos Card&#237;acos</kwd>
      </kwd-group>
      <counts>
        <fig-count count="2"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="5"/>
        <page-count count="4"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <sec sec-type="intro">
      <title>Introdu&#231;&#227;o</title>
      <p>A hipoplasia do cora&#231;&#227;o esquerdo caracteriza-se por dimens&#245;es muito reduzidas das cavidades card&#237;acas esquerdas, representadas pelo &#225;trio esquerdo, valva mitral, ventr&#237;culo esquerdo, anel a&#243;rtico e aorta ascendente.<sup><xref rid="B1" ref-type="bibr">1</xref></sup> A circula&#231;&#227;o sist&#234;mica, assim, passa a ser dependente do canal arterial com fluxo reverso da art&#233;ria pulmonar hipertensa &#224; aorta descendente e tamb&#233;m &#224; aorta ascendente. A circula&#231;&#227;o coron&#225;ria tamb&#233;m &#233; dependente desse fluxo reverso, raz&#227;o da grande chance de infarto do mioc&#225;rdio, mesmo nos primeiros dias de vida. Torna-se f&#225;cil imaginar que, na diminui&#231;&#227;o da press&#227;o arterial pulmonar ou do calibre do canal arterial, haja evolu&#231;&#227;o desfavor&#225;vel para baixo d&#233;bito card&#237;aco. O cora&#231;&#227;o direito se mostra dilatado e comunica&#231;&#227;o interatrial acompanha invariavelmente este defeito. Quando este pertuito se mostra de dimens&#245;es tamb&#233;m reduzidas, conhecido como restritivo, ocasiona hipertens&#227;o pulmonar retr&#243;grada. Por outro lado, quando de dimens&#245;es maiores pode favorecer a involu&#231;&#227;o mais r&#225;pida da hipertens&#227;o pulmonar, com quadro congestivo e de baixo d&#233;bito. Nos raros casos de septo interatrial &#237;ntegro, a drenagem an&#244;mala das veias pulmonares subsiste a fim da manuten&#231;&#227;o e viabilidade da circula&#231;&#227;o. Constitui-se a hipoplasia do cora&#231;&#227;o esquerdo na quarta cardiopatia mais frequente no per&#237;odo neonatal, com alta mortalidade, ainda neste per&#237;odo, e corresponde a 1,5% de todas as cardiopatias cong&#234;nitas.</p>
      <p><bold>Como se exterioriza e evolui: </bold>A instabilidade din&#226;mica favorece o advento de sinais e sintomas muito precoces na vida, nas primeiras horas ou dias de vida. Caracteriza-se por quadro congestivo (com comunica&#231;&#227;o interatrial grande) ou por baixo d&#233;bito sist&#234;mico (diminui&#231;&#227;o da press&#227;o arterial pulmonar e/ou constri&#231;&#227;o do canal arterial), com surgimento de palidez, dispneia, desconforto, irritabilidade e cianose vari&#225;vel. O quadro mais favor&#225;vel corresponde &#224;quele com comunica&#231;&#227;o interatrial restritiva, que em vista da manuten&#231;&#227;o da hipertens&#227;o pulmonar, o d&#233;bito card&#237;aco passa a ser mantido mais satisfatoriamente. Pulsos mais amplos nos membros inferiores e diminu&#237;dos nos superiores, ao lado de sopro sist&#243;lico discreto com segunda bulha hiperfon&#233;tica na &#225;rea pulmonar, sobrecarga de c&#226;maras card&#237;acas direitas no eletrocardiograma e cardiomegalia decorrente das cavidades direitas, constituem-se em elementos diagn&#243;sticos. Na forma restritiva predomina a cianose, sem sopros e a congest&#227;o venocapilar pulmonar expressa a raz&#227;o da hipertens&#227;o pulmonar retr&#243;grada, respons&#225;vel pela manuten&#231;&#227;o do fluxo sist&#234;mico.</p>
      <sec>
        <title>Como se trata</title>
        <p><bold>Cl&#237;nica: </bold>O uso at&#233; profil&#225;tico da prostaglandina (0,05 a 0,1 mcg/Kg/min), logo ap&#243;s o nascimento, torna-se medida capital para a preserva&#231;&#227;o do fluxo sist&#234;mico atrav&#233;s do canal arterial. Drogas vasoativas tipo dobutamina, dopamina e adrenalina se sobrep&#245;em afim da manuten&#231;&#227;o da press&#227;o pulmonar adequada, e tamb&#233;m para manter o d&#233;bito card&#237;aco.</p>
        <p>Caso necessitem de intuba&#231;&#227;o endotraqueal, &#233; imprescind&#237;vel que a fra&#231;&#227;o inspirada de oxig&#234;nio n&#227;o ultrapasse a 25% para evitar a vasodilata&#231;&#227;o pulmonar com consequente diminui&#231;&#227;o do d&#233;bito card&#237;aco. Essas medidas se constituem em suporte para a obten&#231;&#227;o da estabiliza&#231;&#227;o cl&#237;nica (satura&#231;&#227;o de oxig&#234;nio em 80 a 85%) para evitar complica&#231;&#245;es pr&#233;-operat&#243;rias, de risco cir&#250;rgico maior, como infarto do mioc&#225;rdio, arritmias, disfun&#231;&#227;o ventricular, insufici&#234;ncia tric&#250;spide e baixo d&#233;bito sist&#234;mico.</p>
        <p><bold>Cirurgia: </bold>Duas t&#233;cnicas principais s&#227;o indicadas para a corre&#231;&#227;o paliativa da hipoplasia do cora&#231;&#227;o esquerdo. A mais empregada &#233; a opera&#231;&#227;o de Norwood cl&#225;ssica (transforma&#231;&#227;o para anomalia tipo atresia pulmonar e dependente do Blalock-Taussig modificado) ou pela variante de Sano (transforma&#231;&#227;o para anomalia tipo dupla via de sa&#237;da de ventr&#237;culo direito com conex&#227;o por tubo sem valva, de 5 mm de di&#226;metro, entre o ventr&#237;culo direito e o tronco pulmonar). Em ambas t&#233;cnicas, o tronco pulmonar &#233; seccionado transversalmente, junto &#224; bifurca&#231;&#227;o das art&#233;rias pulmonares e a ele se anastomosa a aorta ascendente, criando assim ampla conex&#227;o do ventr&#237;culo direito &#224; aorta. Opera&#231;&#227;o h&#237;brida tamb&#233;m pode ser realizada, com coloca&#231;&#227;o de <italic>stent</italic> no canal arterial, bandagem das art&#233;rias pulmonares e amplia&#231;&#227;o da comunica&#231;&#227;o interatrial. A maior vantagem dessa t&#233;cnica reside na elimina&#231;&#227;o da parada circulat&#243;ria diminuindo o risco operat&#243;rio nesta 1<sup>a</sup> etapa. A indica&#231;&#227;o dessa t&#233;cnica h&#237;brida toma vulto principalmente em situa&#231;&#245;es cl&#237;nicas desfavor&#225;veis em pacientes de alto risco, como na aus&#234;ncia de comunica&#231;&#227;o interatrial, em baixo peso corporal, no choque cardiog&#234;nico, em idades superiores a 14 dias e em centros ainda com alta mortalidade operat&#243;ria.</p>
        <p><bold>Como evolui ap&#243;s a opera&#231;&#227;o: </bold>O equil&#237;brio entre as resist&#234;ncias pulmonar e sist&#234;mica deve ser mantido durante todo o tempo de p&#243;s-operat&#243;rio. Esse aspecto &#233; melhor obtido com a opera&#231;&#227;o de Norwood-Sano, pois, nesta variante, n&#227;o h&#225; desvio de sangue da circula&#231;&#227;o sist&#234;mica atrav&#233;s do Blalock-Taussig, a t&#233;cnica cl&#225;ssica. Assim, o p&#243;s-operat&#243;rio se torna mais est&#225;vel, a perfus&#227;o coron&#225;ria aumenta, assim como a espl&#226;ncnica e ainda diminui a sobrecarga de volume do ventr&#237;culo direito e a mortalidade, at&#233; a opera&#231;&#227;o de Glenn. A desvantagem dessa t&#233;cnica &#233; a da ventriculotomia de cerca de 6 mm na via de sa&#237;da ventricular que pode predispor &#224; disfun&#231;&#227;o ventricular, arritmias e insufici&#234;ncia pulmonar. Em rela&#231;&#227;o &#224; t&#233;cnica h&#237;brida, podem surgir problemas evolutivos, como a constri&#231;&#227;o do canal arterial, estenoses das art&#233;rias pulmonares em decorr&#234;ncia das bandagens pr&#233;vias e at&#233; o desenvolvimento inadequado da aorta ascendente.</p>
        <p>Na evolu&#231;&#227;o de qualquer das t&#233;cnicas preconizadas, teme-se o aparecimento de insufici&#234;ncia card&#237;aca e da hipoxemia, mais pronunciadas. Da&#237; a indica&#231;&#227;o precoce, cerca de 6 meses de idade para a 2<sup>a</sup> etapa, pela opera&#231;&#227;o de <italic>Glenn</italic> bidirecional e a 3<sup>a</sup> etapa, para cerca de 18 a 24 meses de idade, a fim de se completar a opera&#231;&#227;o cavopulmonar total.</p>
        <p>A mortalidade total dos portadores de hipoplasia do cora&#231;&#227;o esquerdo segundo a hist&#243;ria natural, j&#225; no primeiro m&#234;s de vida, atualmente foi aliviada para cerca de 40 a 60% deles at&#233; a feitura do princ&#237;pio Fontan.<sup><xref rid="B2" ref-type="bibr">2</xref>-<xref rid="B5" ref-type="bibr">5</xref></sup> Em evolu&#231;&#227;o posterior ao mesmo, a mortalidade tamb&#233;m &#233; alta, cerca de 25% deles em 10 anos e de at&#233; 55% em 30 anos.<sup><xref rid="B2" ref-type="bibr">2</xref>,<xref rid="B3" ref-type="bibr">3</xref></sup></p>
        <p>O prop&#243;sito desta apresenta&#231;&#227;o &#233; mostrar uma boa evolu&#231;&#227;o a longo prazo, superadas todas as fases operat&#243;rias preconizadas, e salientar as prerrogativas necess&#225;rias para essa boa evolu&#231;&#227;o.</p>
      </sec>
    </sec>
    <sec>
      <title>Descri&#231;&#227;o do caso</title>
      <sec>
        <title>Dados cl&#237;nicos</title>
        <p>Paciente de 21 anos &#233; acompanhado desde o nascimento com diagn&#243;stico de hipoplasia do cora&#231;&#227;o esquerdo, submetido &#224; opera&#231;&#227;o de Norwood com 4 dias de vida, t&#233;cnica de Glenn bidirecional com 5 meses e cavopulmonar total com tubo externo n&#227;o fenestrado com 5 anos. Desde ent&#227;o, evolui sem sintomas, em uso de warfarina, espironolactona e enalapril.</p>
        <p>Exame f&#237;sico: eupneico, acian&#243;tico, pulsos normais. Peso: 80 kg, Altura: 185 cm, PA: 110/80 mm Hg, FC: 65 bpm, O2 = 95%. Turg&#234;ncia jugular discreta e aorta discretamente palpada na f&#250;rcula.</p>
        <p>No prec&#243;rdio, <italic>ictus cordis</italic> n&#227;o era palpado e n&#227;o havia impuls&#245;es sist&#243;licas na borda esternal esquerda (BEE). As bulhas card&#237;acas eram normofon&#233;ticas e auscultava-se sopro sist&#243;lico discreto, +/++/4 de intensidade, timbre rude, na BEE baixa. O f&#237;gado n&#227;o era palpado e pulm&#245;es limpos.</p>
      </sec>
      <sec>
        <title>Exames Complementares</title>
        <p><bold>Eletrocardiograma</bold> mostrava ritmo sinusal e morfologia qR em V1 e onda T negativa de V1 a V3, indicativos de sobrecarga acentuada de ventr&#237;culo direito. N&#227;o havia potenciais de ventr&#237;culo esquerdo, com morfologia RS em V6. AP: +10<sup>o</sup>, AQRS: +100<sup>o</sup>, AT: +70<sup>o</sup> (<xref rid="f01" ref-type="fig">Figura 1</xref>).</p>
        <p>
          <fig id="f01">
            <label>Figura 1</label>
            <caption>
              <title>&#8211; Eletrocardiograma salienta a acentuada sobrecarga do ventr&#237;culo direito; a radiografia de t&#243;rax mostra &#225;rea card&#237;aca e trama vascular pulmonar normais com discreto aumento da aorta; e o ecocardiograma em posi&#231;&#227;o de 4 c&#226;maras a hipoplasia acentuada da cavidade ventricular esquerda, estando normal o ventr&#237;culo direito sist&#234;mico.</title>
            </caption>
            <graphic xlink:href="1678-4170-abc-117-01-0142-01012-gf01.tif"/></fig>
        </p>
        <p><bold>Radiografia de t&#243;rax</bold> mostra &#225;rea card&#237;aca e trama vascular pulmonar normais. Havia discreta sali&#234;ncia do arco a&#243;rtico, e arco m&#233;dio retificado (<xref rid="f01" ref-type="fig">Figura 1</xref>).</p>
        <p><bold>Ecocardiograma</bold> mostrou veia cava inferior dilatada (22 mm), tubo externo entre a veia cava inferior e a art&#233;ria pulmonar direita com fluxo laminar em velocidade de 0,68 m/s, anastomose da veia cava superior com a art&#233;ria pulmonar direita com velocidade m&#225;xima de 0,48 m/s. A conex&#227;o atrioventricular esquerda era ausente. Cavidade ventricular direita em conex&#227;o com a neoaorta (antiga valva pulmonar). Comunica&#231;&#227;o interatrial ampla com fluxo da esquerda para a direita. Ventr&#237;culo direito hipertr&#243;fico e dilatado com fun&#231;&#227;o sist&#243;lica preservada. Ventr&#237;culo esquerdo acentuadamente hipopl&#225;sico. Art&#233;rias pulmonares confluentes (<xref rid="f01" ref-type="fig">Figura 1</xref>).</p>
        <p><bold>Tomografia de abdome</bold>: Hepatoesplenomegalia com par&#234;nquima de densidade normal e homog&#234;neo. Veias porta e hep&#225;ticas de calibre normal. Varizes espl&#234;nicas. N&#227;o h&#225; dilata&#231;&#227;o de vias biliares intra ou extra hep&#225;ticas. Demais estruturas abdominais sem altera&#231;&#245;es morfol&#243;gicas.</p>
        <p><bold>Diagn&#243;stico cl&#237;nico: </bold>S&#237;ndrome de hipoplasia do cora&#231;&#227;o esquerdo submetida &#224; opera&#231;&#227;o cavopulmonar total h&#225; 16 anos, em boa evolu&#231;&#227;o a longo prazo.</p>
      </sec>
      <sec>
        <title>Caracter&#237;sticas cl&#237;nicas</title>
        <p><bold>a. Racioc&#237;nio cl&#237;nico: </bold>Os elementos cl&#237;nicos eram compat&#237;veis com a boa evolu&#231;&#227;o da opera&#231;&#227;o de Fontan executada h&#225; 16 anos, em face de estar sem sintomas e em condi&#231;&#227;o cl&#237;nica favor&#225;vel e sem intercorr&#234;ncias. O sopro sist&#243;lico auscultado na borda esternal esquerda n&#227;o apresentava import&#226;ncia patol&#243;gica por ser discreto, respaldado pela aus&#234;ncia de insufici&#234;ncias valvares pelo ecocardiograma. A esperada sobrecarga acentuada do ventr&#237;culo direito, em face de ter se tornado o ventr&#237;culo sist&#234;mico, n&#227;o &#233; acompanhada de disfun&#231;&#227;o, raz&#227;o da preserva&#231;&#227;o da boa evolu&#231;&#227;o cl&#237;nica do paciente.</p>
        <p><bold>Conduta:</bold> A evolu&#231;&#227;o favor&#225;vel cl&#237;nica neste grupo de pacientes com hipoplasia do cora&#231;&#227;o esquerdo decorre sempre da cont&#237;nua preserva&#231;&#227;o da fun&#231;&#227;o ventricular direita, mesmo submetida a uma carga press&#243;rica maior, e por isso o uso da medica&#231;&#227;o vasodilatadora e em conformidade com a estrutura mioc&#225;rdica. O anticoagulante necess&#225;rio por altera&#231;&#245;es do fluxo sist&#234;mico venoso lento acompanha todos os pacientes submetidos &#224; opera&#231;&#227;o de Fontan, a impedir a forma&#231;&#227;o de trombos evolutivos neste sistema.</p>
      </sec>
    </sec>
    <sec sec-type="discussion">
      <title>Discuss&#227;o</title>
      <p>A hipoplasia do cora&#231;&#227;o esquerdo, sem d&#250;vida, continua sendo a anomalia cong&#234;nita card&#237;aca mais temida, mesmo com a diminui&#231;&#227;o da mortalidade, verificada em todos os est&#225;gios evolutivos entre as opera&#231;&#245;es necessariamente realizadas. Houve melhora da conduta imediata ao nascimento na preserva&#231;&#227;o da condi&#231;&#227;o cl&#237;nica com d&#233;bito sist&#234;mico mais adequado, com o uso da prostaglandina E1 e de drogas vasoativas. Na sequ&#234;ncia, o rec&#233;m-nascido tem sido operado em melhor condi&#231;&#227;o cl&#237;nica e, assim, a t&#233;cnica inicial de Norwood-Sano tamb&#233;m se tornou de menor risco, e cerca de 90% tem sobrevivido nesta fase.<sup><xref rid="B5" ref-type="bibr">5</xref></sup> As evolu&#231;&#245;es subsequentes, at&#233; a opera&#231;&#227;o de Glenn e de Fontan, tamb&#233;m se acompanham de menos intercorr&#234;ncias, o que em maior n&#250;mero conseguem ser acompanhados a maior prazo, como o paciente em quest&#227;o. No entanto, apenas 40 a 50% desses pacientes alcan&#231;am a oportunidade da opera&#231;&#227;o paliativa de Fontan.<sup><xref rid="B2" ref-type="bibr">2</xref>,<xref rid="B5" ref-type="bibr">5</xref></sup> Assim, a morbidade de pacientes com hipoplasia do cora&#231;&#227;o esquerdo continua elevada, indicando que mais cuidados devam ser tomados entre as fases operat&#243;rias.<sup><xref rid="B2" ref-type="bibr">2</xref></sup> A evolu&#231;&#227;o posterior &#224; opera&#231;&#227;o de Fontan obedece aos requisitos da t&#233;cnica paliativa funcional com problemas relacionados a maior congest&#227;o venosa, ao menor d&#233;bito card&#237;aco sist&#234;mico, mas na preserva&#231;&#227;o da boa fun&#231;&#227;o ventricular se torna mais favor&#225;vel, como o observado. Em observa&#231;&#227;o em 1052 pacientes com cardiopatias tipo ventr&#237;culo &#250;nico, operados na Cl&#237;nica Mayo entre 1973 e 2012, a sobrevida ap&#243;s 10, 20 e 30 anos da opera&#231;&#227;o de Fontan foi de 74%, 61% e 43%. Problemas evolutivos se referem &#224; press&#227;o elevada no &#225;trio esquerdo (&gt;13 mm Hg), drenagem pleural prolongada (&gt;21 dias), arritmias presentes, insufici&#234;ncia renal, enteropatia perdedora de prote&#237;nas, disfun&#231;&#227;o card&#237;aca e reinterven&#231;&#245;es cir&#250;rgicas nas valvas.</p>
      <p>Sem d&#250;vida, os desafios continuam, mas com sens&#237;veis melhoras desde que Norwood mudou a hist&#243;ria natural deste defeito em 1982.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <title>Refer&#234;ncias</title>
      <ref id="B1">
        <label>1</label>
        <mixed-citation>1. Atik E, Moreira VM. Hipoplasia do cora&#231;&#227;o esquerdo. Atik E, Moreira VM, editors. Imagens e correla&#231;&#245;es em cardiologia pedi&#225;trica. S&#227;o Paulo: Roca; 2011. p. 336-42.</mixed-citation>
        <element-citation publication-type="book">
          <person-group person-group-type="author">
            <name>
              <surname>Atik</surname>
              <given-names>E</given-names>
            </name>
            <name>
              <surname>Moreira</surname>
              <given-names>VM</given-names>
            </name>
          </person-group>
          <chapter-title>Hipoplasia do cora&#231;&#227;o esquerdo</chapter-title>
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      </fn>
      <fn fn-type="other">
        <p>Aprova&#231;&#227;o &#233;tica e consentimento informado</p>
        <p>Este artigo n&#227;o cont&#233;m estudos com humanos ou animais realizados por nenhum dos autores.</p>
      </fn>
      <fn fn-type="supported-by">
        <p>Fontes de financiamento</p>
        <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
      </fn>
    </fn-group>
  </back>
  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Research Letter</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Left Heart Hypoplasia Evolving Up to 21 Years, After Total Cavopulmonary Operation Performed at 5 Years of Age</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0001-7773-4174</contrib-id>
          <name>
            <surname>Atik</surname>
            <given-names>Edmar</given-names>
          </name>
          <xref ref-type="aff" rid="aff1"/>
        </contrib>
      </contrib-group>
      <aff id="aff1001">
        <country country="BR">Brazil</country>
        <institution content-type="original">Instituto do Cora&#231;&#227;o do Hospital das Cl&#237;nicas da Faculdade de Medicina da Universidade de S&#227;o Paulo, S&#227;o Paulo, SP - Brazil</institution>
      </aff>
      <author-notes>
        <corresp id="c01001"><bold>Mailing Address: Edmar Atik &#8226; </bold>Rua Dona Adma Jafet 74 cj 73. CEP 01308-050, S&#227;o Paulo, SP &#8211; Brazil E-mail: edmar.atik@incor.usp.br </corresp>
        <fn fn-type="con">
          <p>Author Contributions</p>
          <p>Conception and design of the research, Acquisition of data, Analysis and interpretation of the data, Writing of the manuscript and Critical revision of the manuscript for intellectual content: Atik E.</p>
        </fn>
        <fn fn-type="conflict">
          <p>Potential Conflict of Interest</p>
          <p>No potential conflict of interest relevant to this article was reported.</p>
        </fn>
      </author-notes>
      <kwd-group xml:lang="en">
        <kwd>Hypoplastic Left Heart Syndrome</kwd>
        <kwd>Fontan Procedure</kwd>
        <kwd>Cardiac Surgical Procedures</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <sec sec-type="intro">
        <title>Introduction</title>
        <p>Hypoplasia of the left heart is characterized by very small dimensions of the left cardiac cavities, represented by the left atrium, mitral valve, left ventricle, aortic ring and ascending aorta.<sup><xref rid="B1" ref-type="bibr">1</xref></sup> Systemic circulation thus becomes dependent on the ductus arteriosus with reverse flow from the hypertensive pulmonary artery to the descending aorta, and also to the ascending aorta. Coronary circulation is also dependent on this reverse flow, which is why there is a high chance of myocardial infarction, even in the first days of life. It is easy to imagine that, on decreased pulmonary arterial pressure or ductus arteriosus caliber, there is an unfavorable evolution towards low cardiac output. The right heart is enlarged and atrial septal defect invariably accompanies this defect. When this atrial defect appears to be of reduced dimensions, known as restrictive, it causes retrograde pulmonary hypertension. On the other hand, when larger, it may favor the faster involution of pulmonary hypertension, with congestive symptoms and low output. In the rare cases of intact atrial septum, anomalous pulmonary vein drainage remains in order of maintenance and viability of circulation. Left heart hypoplasia is the fourth most common heart disease in the neonatal period, with high mortality, even in this period, and corresponds to 1.5% of all congenital heart diseases.</p>
        <p><bold>How it is externalized and evolves:</bold> Dynamic instability favors the advent of very early signs and symptoms in life, in the first hours or days of life. These signs are characterized by congestive condition (with large atrial defect) or low systemic output (decreased pulmonary arterial pressure and/or constriction of the ductus arteriosus), with pallor, dyspnea, discomfort, irritability and variable cyanosis. The most favorable picture corresponds to the one with restrictive atrial septal defect, which, in view of the maintenance of pulmonary hypertension, the cardiac output is maintained at a satisfactory level.</p>
        <p>Larger pulses in the lower limbs and decreased pulses in the upper limbs, alongside discrete systolic murmur with a second accentuated heart sound in the pulmonary area, overload of the right cardiac chambers on the electrocardiogram and cardiomegaly resulting from the right cavities, constitute diagnostic elements. In the restrictive form, cyanosis predominates, without murmurs and pulmonary venocapillary congestion expresses the reason for retrograde pulmonary hypertension, responsible for maintaining systemic flow.</p>
        <sec>
          <title>How it is Treated</title>
          <p><bold>Clinic:</bold> The prophylactic use of prostaglandin (0.05 to 0.1 mcg/kg/min), right after birth, is a key measure for the preservation of systemic flow through the ductus arteriosus. Vasoactive drugs such as dobutamine, dopamine and adrenaline are added together in order to maintain adequate pulmonary pressure, and to maintain cardiac output.</p>
          <p>If they need endotracheal intubation, it is essential that the fraction of inspired oxygen does not exceed 25%, to avoid pulmonary vasodilation with a consequent decrease in cardiac output. These measures support clinical stabilization (oxygen saturation in 80 to 85%) to avoid preoperative complications, of greater surgical risk, such as myocardial infarction, arrhythmias, ventricular dysfunction, tricuspid regurgitation and low systemic output.</p>
          <p><bold>Surgery:</bold> Two main techniques are indicated for the palliative correction of left heart hypoplasia. The most used one is the classic Norwood operation (transformation to anomaly-type pulmonary atresia and dependent on the modified Blalock-Taussig technique) or by the Sano variant (transformation to anomaly-type double outlet right ventricle with non-valved tube connection, 5 mm in diameter, between the right ventricle and the pulmonary trunk). In both techniques, the pulmonary trunk is sectioned transversely, next to the bifurcation of the pulmonary arteries, and the ascending aorta is anastomosed to it, thus creating a wide connection between the right ventricle and the neoaorta. Hybrid operation can also be performed, with stent placement in the ductus arteriosus, banding of the pulmonary arteries and expansion of the atrial septal defect. The greatest advantage of this technique lies in the elimination of circulatory arrest, decreasing the operative risk in this first stage. Indication of this hybrid technique is particularly important in unfavorable clinical situations involving high-risk patients, such as in the absence of atrial septal defect, low body weight, cardiogenic shock, at ages older than 14 days and in centers with high operative mortality.</p>
          <p><bold>How it evolves after the operation:</bold> The balance between pulmonary and systemic resistance must be maintained throughout the postoperative period. This aspect is best achieved with the Norwood-Sano operation, since in this variant there is no diversion of blood from the systemic circulation through the classic Blalock-Taussig technique. Thus, the postoperative period becomes more stable, both coronary and splanchnic perfusion increase, and right ventricular volume overload and mortality decrease, until the Glenn operation. The disadvantage of this technique is a 6 mm ventriculotomy in the ventricular outflow tract that can predispose to ventricular dysfunction, arrhythmias and pulmonary insufficiency. Regarding the hybrid technique, evolutionary problems may arise, such as constriction of the ductus arteriosus, stenosis of the pulmonary arteries due to previous bandages and even the inadequate development of the ascending aorta.</p>
          <p>In the evolution of any of the recommended techniques, heart failure and hypoxemia, which are more pronounced, are feared. Hence the early indication, about 6 months of age for the 2<sup>nd</sup> stage, by the bidirectional Glenn operation and the 3<sup>rd</sup> stage, for about 18 to 24 months of age, in order to complete the total cavopulmonary operation.</p>
          <p>The total mortality of patients with hypoplasia of the left heart according to natural history, in the first month of life, has now been alleviated for about 40 to 60% of them until the completion of the Fontan<sup><xref rid="B2" ref-type="bibr">2</xref>-<xref rid="B5" ref-type="bibr">5</xref></sup> principle. In subsequent evolution, mortality is also high, about 25% of them in 10 years and up to 55% in 30 years.<sup><xref rid="B2" ref-type="bibr">2</xref>,<xref rid="B3" ref-type="bibr">3</xref></sup></p>
          <p>The purpose of this presentation is to show a good long-term evolution, overcoming all the recommended operative phases, and to highlight the necessary prerogatives for this good evolution.</p>
        </sec>
      </sec>
      <sec>
        <title>Case description</title>
        <sec>
          <title>Clinical data</title>
          <p>A 21-year-old patient has been followed up since birth with diagnosis of left heart hypoplasia, who underwent Norwood operation at 4 days of life, 5-month bidirectional Glenn technique and total cavopulmonary anastomosis at 5 years with a non-fenestrated external tube. Since then, he has evolved without symptoms, using warfarin, spironolactone and enalapril.</p>
          <p>Physical examination: eupneic, acyanotic, normal pulses. Weight: 80 kg, Height: 185 cm, BP: 110/80 mm Hg, CF: 65 bpm, O2 = 95%. Discreet jugular turgescence and aorta slightly palpated at the suprasternal notch.</p>
          <p>In the precordium, apical impulse was not palpable and there were no systolic impulses at the left external border (LEB). The cardiac sounds were normal in intensity and a mild systolic murmur was heard, +/++/4 intensity, rough, in the low LEB. The liver was not palpable and the lungs were clean.</p>
        </sec>
        <sec>
          <title>Complementary Exams</title>
          <p><bold>Electrocardiogram </bold>showed sinus rhythm and qR morphology in V1 and negative T waves from V1 to V3, indicative of severe right ventricular overload. There were no left ventricular potentials, with RS morphology in V6. AP:+10<sup>o</sup>, AQRS: +100<sup>o</sup>, AT: +70<sup>o</sup> (<xref rid="f01001" ref-type="fig">Figure 1</xref>).</p>
          <p>
            <fig id="f01001">
              <label>Figure 1</label>
              <caption>
                <title/>
              </caption>
              <graphic xlink:href="1678-4170-abc-117-01-0142-01012-gf01-en.tif"/></fig>
          </p>
          <p><bold>Chest radiography</bold> shows normal cardiac area and pulmonary vascular network. There was a slight protrusion of the aortic arch, and a rectified medium arch (<xref rid="f01001" ref-type="fig">Figure 1</xref>).</p>
          <p><bold>Echocardiogram</bold> showed dilated inferior vena cava (22 mm), external tube between the inferior vena cava and the right pulmonary artery with a laminar flow at a speed of 0.68 m/s, anastomosis of the superior vena cava with the right pulmonary artery with a maximum velocity of 0.48 m/s. The left atrioventricular connection was absent. Right ventricular cavity in connection with the neoaorta (former pulmonary trunk and valve). Wide interatrial communication with flow from left to right. Hypertrophic and dilated right ventricle with preserved systolic function. Left ventricle markedly hypoplastic. Confluent pulmonary arteries (<xref rid="f01001" ref-type="fig">Figure 1</xref>).</p>
          <p><bold>Abdominal tomography:</bold> Hepatosplenomegaly with normal and homogeneous density parenchyma. Normal caliber hepatic and portal veins. Varicose splenic veins. No dilation of intra or extrahepatic bile ducts. Other abdominal structures without morphological abnormalities.</p>
          <p><bold>Clinical diagnosis:</bold> Left heart hypoplasia syndrome submitted to total cavopulmonary operation 16 years ago, in good long-term evolution.</p>
        </sec>
        <sec>
          <title>Clinical Characteristics</title>
          <p><bold>a. Clinical reasoning:</bold> The clinical elements were compatible with the good evolution of the Fontan operation performed 16 years ago, due to absence of symptoms and complications, and a favorable clinical condition. Systolic murmur auscultated on the left sternal border was not of pathological importance because it was discreet, supported by the absence of valve insufficiencies on echocardiogram. The expected marked right ventricular overload, as this has become the systemic ventricle, is not accompanied by dysfunction, which is why the patient&#8217;s good clinical evolution has been preserved.</p>
          <p><bold>Management:</bold> The favorable clinical evolution in this group of patients with hypoplasia of the left heart always results from continuous preservation of right ventricular function, even when subjected to a higher-pressure load and, for this reason, vasodilator medication was administered according to the myocardial structure. Anticoagulants required due to slow systemic venous flow abnormalities accompany all patients undergoing the Fontan operation, preventing the formation of evolutionary thrombi in this system.</p>
        </sec>
      </sec>
      <sec sec-type="discussion">
        <title>Discussion</title>
        <p>Left heart hypoplasia is undoubtedly the most feared congenital cardiac anomaly, even with the decrease in mortality, as found in all evolutionary stages between the operations necessarily performed. There was an improvement in the immediate management at birth in preserving the clinical condition with more adequate systemic output, with the use of prostaglandin E1 and vasoactive drugs. As a result, the newborn has been operated in a better clinical condition, so the initial Norwood-Sano technique has also become less risky, and about 90% has survived in this phase.<sup><xref rid="B5" ref-type="bibr">5</xref></sup> Subsequent developments, up to the Glenn and Fontan operation, are also accompanied by fewer complications, which in greater numbers manage to be followed up in the long term, as the patient in question. However, only 40 to 50% of these patients have the chance of undergoing the Fontan palliative operation.<sup><xref rid="B2" ref-type="bibr">2</xref>,<xref rid="B5" ref-type="bibr">5</xref></sup> Thus, the morbidity of patients with hypoplasia of the left heart remains high, indicating that more care should be taken between the operative phases.<sup><xref rid="B2" ref-type="bibr">2</xref></sup> Evolution after the Fontan operation obeys the requirements of the functional palliative technique with problems related to greater venous congestion, lower systemic cardiac output but, in the preservation of good ventricular function, it turns out to be more favorable, as observed. Under observation, of 1052 patients with single ventricular type heart defects, operated on at the Mayo Clinic between 1973 and 2012, survival after 10, 20 and 30 years after the Fontan operation was 74%, 61% and 43%. Evolutionary problems refer to high left atrial pressure (&gt;13 mm Hg), prolonged pleural drainage (&gt;21 days), arrhythmias, renal failure, protein-losing enteropathy, cardiac dysfunction and surgical valve interventions.</p>
        <p>Without a doubt, the challenges remain, but with noticeable improvements since Norwood changed the natural history of the left heart hypoplasia syndrome defects in 1982.</p>
      </sec>
    </body>
    <back>
      <fn-group>
        <fn fn-type="other">
          <p>Study Association</p>
          <p>This study is not associated with any thesis or dissertation work.</p>
        </fn>
        <fn fn-type="other">
          <p>Ethics approval and consent to participate</p>
          <p>This article does not contain any studies with human participants or animals performed by any of the authors.</p>
        </fn>
      </fn-group>
      <fn-group>
        <fn fn-type="supported-by">
          <p>Sources of Funding</p>
          <p>There were no external funding sources for this study.</p>
        </fn>
      </fn-group>
    </back>
  </sub-article>
</article>
