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  <front>
    <journal-meta>
      <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-loc>S&#227;o Paulo, SP, Brazil</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">XMVQymHs7mPR93HPhgvVv3D</article-id>
      <article-id pub-id-type="other">00018</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2011000600018</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(11)09600618</article-id>
      <article-id pub-id-type="doi">10.1590/S0066-782X2011000600018</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Relato de Caso</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Hipertens&#227;o pulmonar em lactente associada a pulm&#227;o em ferradura: relato de caso</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Neves</surname>
            <given-names>Juliana Rodrigues</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
          <xref ref-type="aff" rid="aff03"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Arrieta</surname>
            <given-names>Santiago Raul</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Cavalcanti</surname>
            <given-names>Catarina V</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Mattos</surname>
            <given-names>Sandra S</given-names>
          </name>
          <xref ref-type="aff" rid="aff03"/>
        </contrib>
      </contrib-group>
      <aff id="aff03">
        <addr-line>
          <named-content content-type="city">Recife</named-content>
          <named-content content-type="state"/>
        </addr-line>
        <institution content-type="orgname">Unidade de Cardiologia Materno-Fetal</institution>
        <country country="BR">Brazil</country>
      </aff>
      <aff id="aff01">
        <institution content-type="orgname">Pronto-Socorro Cardiol&#243;gico de Pernambuco</institution>
      </aff>
      <aff id="aff02">
        <addr-line>
          <named-content content-type="state">Pernambuco</named-content>
        </addr-line>
        <institution content-type="orgname">Instituto de Medicina Integral Professor Fernando Figueira</institution>
        <country country="BR">Brazil</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>06</month>
        <year>2011</year>
      </pub-date>
      <volume>96</volume>
      <issue>6</issue>
      <fpage>e116</fpage>
      <lpage>e118</lpage>
      <history>
        <date date-type="received">
          <day>20</day>
          <month>02</month>
          <year>2008</year>
        </date>
        <date date-type="accepted">
          <day>30</day>
          <month>11</month>
          <year>2009</year>
        </date>
        <date date-type="rev-recd">
          <day>02</day>
          <month>08</month>
          <year>2009</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/4.0/" xml:lang="en">
          <license-p>This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</license-p>
        </license>
      </permissions>
      <abstract>
        <p>Relatamos caso de lactente jovem com desconforto respirat&#243;rio precoce e hipertens&#227;o pulmonar, diagnosticado como variante de pulm&#227;o em ferradura, e revisamos literatura a cerca desta rara malforma&#231;&#227;o pulmonar e suas repercuss&#245;es card&#237;acas e hemodin&#226;micas.</p>
      </abstract>
      <kwd-group xml:lang="pt" kwd-group-type="author-generated">
        <kwd>Cardiopatias cong&#234;nitas</kwd>
        <kwd>hipertens&#227;o pulmonar</kwd>
        <kwd>lactente</kwd>
      </kwd-group>
      <pub-date publication-format="electronic" date-type="pub">
        <day>03</day>
        <month>10</month>
        <year>2011</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>RELATO DE CASO</bold>
    </p>
    <p>
      <bold>Hipertens&#227;o pulmonar em lactente associada a pulm&#227;o em ferradura: relato de caso</bold>
    </p>
    <p>
      <bold>Juliana Rodrigues Neves<sup>I,II,III</sup>; Santiago Raul Arrieta<sup>II</sup>; Catarina V. Cavalcanti<sup>I</sup>; Sandra S. Mattos<sup>III</sup></bold>
    </p>
    <p><sup>I</sup>Pronto-Socorro Cardiol&#243;gico de Pernambuco - PROCAPE</p>
    <p><sup>II</sup>Instituto de Medicina Integral Prof. Fernando Figueira - IMIP</p>
    <p><sup>III</sup>Unidade de Cardiologia Materno-Fetal - UCMF, Recife, PE - Brasil</p>
    <p>
      <xref ref-type="corresp" rid="end">Correspond&#234;ncia</xref>
    </p>
    <p>
      <bold>RESUMO</bold>
    </p>
    <p>Relatamos caso de lactente jovem com desconforto respirat&#243;rio precoce e hipertens&#227;o pulmonar, diagnosticado como variante de pulm&#227;o em ferradura, e revisamos literatura a cerca desta rara malforma&#231;&#227;o pulmonar e suas repercuss&#245;es card&#237;acas e hemodin&#226;micas.</p>
    <p><bold>Palavras-chave:</bold> Cardiopatias cong&#234;nitas, hipertens&#227;o pulmonar, lactente.</p>
    <p>
      <bold>Introdu&#231;&#227;o</bold>
    </p>
    <p>Pulm&#227;o em ferradura &#233; uma anomalia cong&#234;nita rara definida como fus&#227;o dos segmentos p&#243;stero-inferiores dos pulm&#245;es. O acometimento do pulm&#227;o direito com hipoplasia &#233; mais frequente e, na maioria dos casos, &#233; associado &#224; s&#237;ndrome da cimitarra. O acometimento do pulm&#227;o esquerdo &#233; excepcional e relacionado &#224; pior evolu&#231;&#227;o, assim como presen&#231;a de malforma&#231;&#245;es card&#237;acas associadas e hipertens&#227;o pulmonar<sup>1,2</sup>.</p>
    <p>Relatamos caso de lactente jovem encaminhado a centro de cardiologia pedi&#225;trica por epis&#243;dios de cianose.</p>
    <p>
      <bold>Relato de caso</bold>
    </p>
    <p>Trata-se de lactente de tr&#234;s meses de vida, sexo feminino, encaminhada a centro de refer&#234;ncia de cardiologia pedi&#225;trica por apresentar dispneia desde o nascimento e epis&#243;dios frequentes de cianose. Ap&#243;s nascimento, a paciente apresentou hip&#243;xia leve e desconforto respirat&#243;rio nas primeiras horas de vida, necessitando suporte com ventila&#231;&#227;o mec&#226;nica assistida. Permaneceu em unidade de terapia intensiva (UTI) neonatal por 30 dias e obteve alta hospitalar aos 40 dias de vida, ainda com desconforto respirat&#243;rio e dificuldade alimentar. Aos dois meses de vida, apresentou epis&#243;dio de cianose, tendo sido diagnosticado pneumonia &#224; esquerda, necessitando suporte ventilat&#243;rio por 04 dias e antibioticoterapia espec&#237;fica. Como n&#227;o houve melhora do quadro ap&#243;s terapia e persistindo com epis&#243;dios frequentes de cianose, foi encaminhada a servi&#231;o terci&#225;rio em cardiologia pedi&#225;trica.</p>
    <p>&#192; admiss&#227;o, apresentava-se com estado geral comprometido, taquidispneica em grau moderado, com leve cianose central sob cateter nasal de oxig&#234;nio (O<sub>2</sub>) 3 l/min. &#192; inspe&#231;&#227;o do t&#243;rax, evidenciava-se abaulamento de prec&#243;rdio e hiperdinamismo, al&#233;m de intenso desconforto respirat&#243;rio. &#192; ausculta card&#237;aca, encontrava-se em ritmo card&#237;aco regular, taquic&#225;rdica, com hiperfonese do componente pulmonar de segunda bulha, sem sopros. &#192; ausculta pulmonar, evidenciava-se diminui&#231;&#227;o do murm&#250;rio vesicular &#224; esquerda e estertores subcrepitantes difusos, al&#233;m de discreto estridor inspirat&#243;rio. Os pulsos eram presentes e sim&#233;tricos. No abdome, palpava-se o f&#237;gado a 4,0 cm do rebordo costal direito.</p>
    <p>A paciente foi admitida em UTI cardiopedi&#225;trica para estabiliza&#231;&#227;o hemodin&#226;mica, onde foi iniciada ventila&#231;&#227;o n&#227;o invasiva com fra&#231;&#227;o inspirada de O<sub>2</sub> de 0,5, furosemida de 3,0 mg/kg/dia e dobutamina de 5,0 &#181;g/kg/min. Evoluiu com estabiliza&#231;&#227;o cl&#237;nica, desmame de suporte ventilat&#243;rio e inotr&#243;pico, de tal modo que, no 5&#186; dia ap&#243;s admiss&#227;o, encontrava-se em ar ambiente com taquidispneia leve, mantendo satura&#231;&#227;o de O<sub>2</sub> em torno de 96%, em uso de furosemida de 3,0 mg/kg/dia e digoxina de 0,01 mg/kg/dia. Foi ent&#227;o iniciada investiga&#231;&#227;o cl&#237;nica.</p>
    <p>A radiografia do t&#243;rax mostrava redu&#231;&#227;o do volume do pulm&#227;o esquerdo, com desvio das estruturas do mediastino para este lado (<xref ref-type="fig" rid="a18fig01">Figura 1a</xref>). Trazia do hospital de origem tomografia computadorizada de t&#243;rax, cuja avalia&#231;&#227;o local diagnosticava hipoplasia de pulm&#227;o esquerdo. An&#225;lise posterior, apesar da m&#225; qualidade t&#233;cnica do exame, detectava tamb&#233;m imagem sugestiva de continuidade entre os lobos pulmonares inferiores (<xref ref-type="fig" rid="a18fig01">Figura 1b</xref>).</p>
    <p><fig id="a18fig01"/>&#13;
&#160;&#13;
</p>
    <p>
      <fig id="a18fig01a">
        <graphic xlink:href="1678-4170-abc-96-06-e116-00018-gf01.jpg"/></fig>
    </p>
    <p>&#13;
  <fig id="a18fig01xfig1b"/><fig id="a18fig01b"><graphic xlink:href="1678-4170-abc-96-06-e116-00018-gf02.jpg"/></fig></p>
    <p>Ecocardiograma transtor&#225;cico identificou aumento de c&#226;maras card&#237;acas direitas com sinais de hipertens&#227;o arterial pulmonar e pequena comunica&#231;&#227;o interatrial (CIA) do tipo <italic>ostium secundum.</italic></p>
    <p>Foi realizado cateterismo card&#237;aco que evidenciou hipertens&#227;o arterial pulmonar importante (<xref ref-type="table" rid="a18tab01m">Tabela 1</xref>).</p>
    <p content-type="asset">
      <table-wrap id="a18tab01m">
        <graphic xlink:href="1678-4170-abc-96-06-e116-00018-gt01.jpg"/></table-wrap>
    </p>
    <p>&#192; angiografia, observava-se ramo da art&#233;ria pulmonar direita dirigindo-se ao istmo do pulm&#227;o esquerdo, n&#227;o ficando bem evidenciada a origem da art&#233;ria pulmonar esquerda (pulm&#227;o esquerdo hipopl&#225;sico), com o retorno venoso se fazendo paralelamente a este ramo arterial para o istmo pulmonar, drenando em &#225;trio esquerdo (<xref ref-type="fig" rid="a18fig01">Figuras 1c</xref>, <xref ref-type="fig" rid="a18fig01">1d</xref> e <xref ref-type="fig" rid="a18fig01">1e</xref>).</p>
    <p>Ap&#243;s o cateterismo card&#237;aco, a crian&#231;a foi readmitida em UTI para recupera&#231;&#227;o anest&#233;sica e foi iniciada terapia medicamentosa para hipertens&#227;o pulmonar com sildenafila nas doses preconizadas. No terceiro dia ap&#243;s o cateterismo, encontrava-se em ar ambiente, com as medica&#231;&#245;es prescritas anteriormente e aguardando alta para enfermaria, quando apresentou epis&#243;dio s&#250;bito de cianose com bradicardia sinusal que evoluiu para assistolia, sem resposta &#224;s manobras de reanima&#231;&#227;o, evoluindo para o &#243;bito. O epis&#243;dio foi interpretado pelo plantonista-assistente como "crise de hipertens&#227;o pulmonar".</p>
    <p>Apesar de ciente da gravidade do quadro e esclarecida quanto &#224; import&#226;ncia da elucida&#231;&#227;o diagn&#243;stica, a genitora n&#227;o autorizou estudo anatomopatol&#243;gico, o que impossibilitou a confirma&#231;&#227;o anat&#244;mica dos dados aqui relatados.</p>
    <p>
      <bold>Revis&#227;o da literatura e considera&#231;&#245;es</bold>
    </p>
    <p>O pulm&#227;o em ferradura caracteriza-se pela presen&#231;a de istmo de par&#234;nquima pulmonar que se estende atrav&#233;s da linha m&#233;dia, conectando as regi&#245;es p&#243;stero-basais de ambos os pulm&#245;es, por tr&#225;s do cora&#231;&#227;o e anterior &#224; aorta descendente. Desde sua descri&#231;&#227;o na d&#233;cada de 60 (Spencer, 1962), foram relatados cerca de 40 casos na literatura mundial, em sua maioria associados &#224; hipoplasia do pulm&#227;o direito e com frequ&#234;ncia associados &#224; s&#237;ndrome de cimitarra. H&#225; apenas um caso descrito em um feto de 19 semanas, onde o istmo pulmonar estava localizado na por&#231;&#227;o apical dos pulm&#245;es, o que levou a reflex&#245;es sobre a origem embriol&#243;gica desta malforma&#231;&#227;o<sup>1-3</sup>.</p>
    <p>Na maioria dos casos, a sintomatologia cl&#237;nica inicia-se precocemente com problemas pulmonares em crian&#231;as jovens, lactentes e neonatos. Desconforto respirat&#243;rio frequente, pneumonias de repeti&#231;&#227;o e epis&#243;dios de cianose s&#227;o os achados mais comuns. Hipertens&#227;o pulmonar tem sido implicada na evolu&#231;&#227;o precoce de tais pacientes, apesar de n&#227;o ser regra<sup>1,4</sup>. A s&#237;ndrome de cimitarra associa-se em 15% dos casos com o pulm&#227;o em ferradura e, apesar das semelhan&#231;as morfol&#243;gicas entre a s&#237;ndrome com ou sem esta associa&#231;&#227;o, sua apresenta&#231;&#227;o cl&#237;nica &#233; diferente<sup>5</sup>. Os pacientes com pulm&#227;o em ferradura apresentam mais cedo sintomatologia evidente e necessidade precoce de cirurgia, conforme discuss&#227;o a seguir. Cardiopatias cong&#234;nitas ocorrem em 25% dos casos, sendo a comunica&#231;&#227;o interatrial a mais comum (50%). Outras les&#245;es incluem comunica&#231;&#227;o interventricular, persist&#234;ncia do canal arterial, tetralogia de Fallot, drenagem an&#244;mala total de veias pulmonares (em caso descrito recentemente em literatura nacional) e coarcta&#231;&#227;o da aorta<sup>6,7</sup>.</p>
    <p>Nosso paciente apresentou sintomatologia em fase muito precoce da vida, com hipertens&#227;o pulmonar severa, associada &#224; comunica&#231;&#227;o interatrial e anomalia de drenagem venosa pulmonar, fatores relacionados ao pior progn&#243;stico.</p>
    <p>Na radiografia de t&#243;rax, observa-se hipoplasia de um dos pulm&#245;es e desvio das estruturas do mediastino para o mesmo lado, por&#233;m n&#227;o h&#225; achado caracter&#237;stico da malforma&#231;&#227;o<sup>1</sup>. Tomografia computadorizada de t&#243;rax demonstra hipoplasia pulmonar unilateral com istmo que se estende al&#233;m da linha m&#233;dia. Geralmente, o pulm&#227;o direito &#233; afetado, entretanto, assim como o caso aqui relatado, foram descritos casos de acometimento de pulm&#227;o esquerdo, sendo observado ainda que o istmo origina-se do pulm&#227;o hipopl&#225;sico em todos os casos<sup>2,8</sup>. A defini&#231;&#227;o do diagn&#243;stico &#233; feita por broncografia ou angiografia quando &#233; definido o suprimento br&#244;nquico e vascular an&#244;malo para o istmo pulmonar. O cateterismo card&#237;aco, al&#233;m de demonstrar a anatomia vascular arterial, &#233; importante ferramenta na avalia&#231;&#227;o da drenagem venosa do pulm&#227;o afetado, podendo haver ou n&#227;o altera&#231;&#227;o e obstru&#231;&#227;o em seu trajeto, e no diagn&#243;stico e estudo hemodin&#226;mico dos casos associados &#224; hipertens&#227;o pulmonar<sup>1,2</sup>.</p>
    <p>No caso em quest&#227;o, a possibilidade diagn&#243;stica foi aventada apenas ap&#243;s o cateterismo card&#237;aco, quando o tratamento com sildenafila foi institu&#237;do na tentativa de minimizar a sintomatologia relacionada &#224; hipertens&#227;o arterial pulmonar, a qual parece ter contribu&#237;do sobremaneira para o desfecho do caso.</p>
    <p>Quando poss&#237;vel, o tratamento cir&#250;rgico est&#225; indicado na presen&#231;a de infec&#231;&#245;es recorrentes, "curto-circuito" esquerdo-direito significativo (Qp:Qs &gt; 2:1) na presen&#231;a de defeitos card&#237;acos associados e hipertens&#227;o pulmonar progressiva. Deve-se realizar corre&#231;&#227;o das anomalias intracard&#237;acas existentes ou, se h&#225; infec&#231;&#245;es recorrentes, ressec&#231;&#227;o do pulm&#227;o afetado. Devido &#224; m&#225; evolu&#231;&#227;o destes pacientes no p&#243;s-operat&#243;rio, se n&#227;o h&#225; sintomatologia ou "curto-circuito" sist&#234;mico-pulmonar significativo o tratamento conservador &#233; preconizado<sup>1</sup>.</p>
    <p>Aqui, relatamos caso raro de pulm&#227;o em ferradura com acometimento de pulm&#227;o esquerdo, curso cl&#237;nico tempestuoso e hipertens&#227;o pulmonar severa. Como n&#227;o foi poss&#237;vel estudo anatomopatol&#243;gico do caso em quest&#227;o, alguns coment&#225;rios se fazem necess&#225;rios. Apesar de descrito de forma isolada como aqui apresentamos, o pulm&#227;o em ferradura &#233; comumente relacionado &#224; s&#237;ndrome da cimitarra. Assim, de forma isolada, a origem aberrante da art&#233;ria pulmonar esquerda poderia caracterizar uma forma de anel vascular, como o <italic>sling</italic> da art&#233;ria pulmonar esquerda, mas sem compress&#227;o da traqueia distal. Poder&#237;amos questionar tamb&#233;m se o curso anormal desta art&#233;ria n&#227;o seria uma varia&#231;&#227;o da ramifica&#231;&#227;o arterial pulmonar.</p>
    <p>De qualquer maneira, consideramos importante a descri&#231;&#227;o do caso para que o reconhecimento desta doen&#231;a seja poss&#237;vel em seu est&#225;gio precoce, pois apresenta associa&#231;&#227;o com graus vari&#225;veis de hipertens&#227;o pulmonar de car&#225;ter evolutivo e, de forma geral, progn&#243;stico prec&#225;rio.</p>
    <p>
      <bold>Potencial Conflito de Interesses</bold>
    </p>
    <p>Declaro n&#227;o haver conflito de interesses pertinentes.</p>
    <p>
      <bold>Fontes de Financiamento</bold>
    </p>
    <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
    <p>
      <bold>Vincula&#231;&#227;o Acad&#234;mica</bold>
    </p>
    <p>N&#227;o h&#225; vincula&#231;&#227;o deste estudo a programas de p&#243;s-gradua&#231;&#227;o.</p>
    <p>
      <fn id="end" fn-type="corresp">
        <label>
          <bold>Correspond&#234;ncia:</bold>
        </label>
        <p> Juliana Rodrigues Neves</p>
        <p> Av. Bernardo Vieira de Melo, 4989/1401 - Candeias</p>
        <p> 54440-620 - Jaboat&#227;o dos Guararapes, PE - Brasil</p>
        <p> E-mail: </p>
        <p><email xlink:href="ju_neves@cardiol.br">ju_neves@cardiol.br</email>, </p>
        <p>
          <email xlink:href="ju.neves2000@gmail.com">ju.neves2000@gmail.com</email>
        </p>
      </fn>
    </p>
    <p>Artigo recebido em 20/02/08; revisado recebido em 02/08/09; aceito em 30/11/09.</p>
  </body>
  <back>
    <ref-list>
      <ref id="B1">
        <mixed-citation>1. Frank JL, Poole CA, Rosas G. Horseshoe lung: clinical, pathologic, and radiologic features and a new plain film finding. AJR Am J Roentgenol. 1986;146(2):217-26.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung: clinical, pathologic, and radiologic features and a new plain film finding</article-title>
          <source>AJR Am J Roentgenol</source>
          <date>
            <year>1986</year>
          </date>
          <fpage>217</fpage>
          <lpage>26</lpage>
          <issue>2</issue>
          <volume>146</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Frank</surname>
              <given-names>JL</given-names>
            </name>
            <name>
              <surname>Poole</surname>
              <given-names>CA</given-names>
            </name>
            <name>
              <surname>Rosas</surname>
              <given-names>G</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B2">
        <mixed-citation>2. Lutterman J, Jedeikin R, Cleveland DC. Horseshoe lung with left lung hypoplasia and critical pulmonary venous stenosis. Ann Thorac Surg. 2004;77(3):1085-7.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung with left lung hypoplasia and critical pulmonary venous stenosis</article-title>
          <source>Ann Thorac Surg</source>
          <date>
            <year>2004</year>
          </date>
          <fpage>1085</fpage>
          <lpage>7</lpage>
          <issue>3</issue>
          <volume>77</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Lutterman</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Jedeikin</surname>
              <given-names>R</given-names>
            </name>
            <name>
              <surname>Cleveland</surname>
              <given-names>DC</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B3">
        <mixed-citation>3. M&#228;nner J, Jakob C, Steding G, F&#252;zesi L. Horseshoe lung: report on a new variant - "inverted" horseshoe lung - with embryological reflections on the formal pathogenesis of horseshoe lungs. Ann Anat. 2001;183(3):261-5.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung: report on a new variant - "inverted" horseshoe lung - with embryological reflections on the formal pathogenesis of horseshoe lungs</article-title>
          <source>Ann Anat</source>
          <date>
            <year>2001</year>
          </date>
          <fpage>261</fpage>
          <lpage>5</lpage>
          <issue>3</issue>
          <volume>183</volume>
          <person-group person-group-type="author">
            <name>
              <surname>M&#228;nner</surname>
              <given-names>J</given-names>
            </name>
            <name>
              <surname>Jakob</surname>
              <given-names>C</given-names>
            </name>
            <name>
              <surname>Steding</surname>
              <given-names>G</given-names>
            </name>
            <name>
              <surname>F&#252;zesi</surname>
              <given-names>L</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B4">
        <mixed-citation>4. Freedom RM, Burrows PE, Moes CA. "Horseshoe lung: report of five new cases. AJR Am J Roentgenol. 1986;146(2):211-5.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung: report of five new cases</article-title>
          <source>AJR Am J Roentgenol</source>
          <date>
            <year>1986</year>
          </date>
          <fpage>211</fpage>
          <lpage>5</lpage>
          <issue>2</issue>
          <volume>146</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Freedom</surname>
              <given-names>RM</given-names>
            </name>
            <name>
              <surname>Burrows</surname>
              <given-names>PE</given-names>
            </name>
            <name>
              <surname>Moes</surname>
              <given-names>CA</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B5">
        <mixed-citation>5. Yoo SJ, Al-Otay A, Babyn P. The relationship between scimitar syndrome, so-called scimitar variant, meandering right pulmonary vein, horseshoe lung and pulmonary arterial sling. Cardiol Young. 2006;16(2):300-4.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>The relationship between scimitar syndrome, so-called scimitar variant, meandering right pulmonary vein, horseshoe lung and pulmonary arterial sling</article-title>
          <source>Cardiol Young</source>
          <date>
            <year>2006</year>
          </date>
          <fpage>300</fpage>
          <lpage>4</lpage>
          <issue>2</issue>
          <volume>16</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Yoo</surname>
              <given-names>SJ</given-names>
            </name>
            <name>
              <surname>Al-Otay</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Babyn</surname>
              <given-names>P</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B6">
        <mixed-citation>6. Hawass ND, Badawi MG, Fatani JA, Meshari AA, Edrees YB. Horseshoe lung with multiple congenital anomalies: case report and review of the literature. Acta Radiol. 1987;28(6):751-4.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung with multiple congenital anomalies: case report and review of the literature</article-title>
          <source>Acta Radiol</source>
          <date>
            <year>1987</year>
          </date>
          <fpage>751</fpage>
          <lpage>4</lpage>
          <issue>6</issue>
          <volume>28</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Hawass</surname>
              <given-names>ND</given-names>
            </name>
            <name>
              <surname>Badawi</surname>
              <given-names>MG</given-names>
            </name>
            <name>
              <surname>Fatani</surname>
              <given-names>JA</given-names>
            </name>
            <name>
              <surname>Meshari</surname>
              <given-names>AA</given-names>
            </name>
            <name>
              <surname>Edrees</surname>
              <given-names>YB</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B7">
        <mixed-citation>7. Matushita JPK, Missiaggia GC, Peixoto RMA, Le&#227;o Filho HM, Dias RS, Tavares Jr WC, et al. Pulm&#227;o em ferradura: relato de caso. Radiol Bras. 2007;40(5):359-61.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Pulm&#227;o em ferradura: relato de caso</article-title>
          <source>Radiol Bras</source>
          <date>
            <year>2007</year>
          </date>
          <fpage>359</fpage>
          <lpage>61</lpage>
          <issue>5</issue>
          <volume>40</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Matushita</surname>
              <given-names>JPK</given-names>
            </name>
            <name>
              <surname>Missiaggia</surname>
              <given-names>GC</given-names>
            </name>
            <name>
              <surname>Peixoto</surname>
              <given-names>RMA</given-names>
            </name>
            <name>
              <surname>Le&#227;o Filho</surname>
              <given-names>HM</given-names>
            </name>
            <name>
              <surname>Dias</surname>
              <given-names>RS</given-names>
            </name>
            <name>
              <surname>Tavares Jr</surname>
              <given-names>WC</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
      <ref id="B8">
        <mixed-citation>8. Ersoz A, Soncul H, Gokgoz L, Kalaycio&#287;lu S, Tunao&#287;lu S, Kaptano&#287;lu M, et al. Horseshoe lung with left lung hypoplasia. Thorax. 1992;47(3):205-6.</mixed-citation>
        <element-citation publication-type="journal">
          <article-title>Horseshoe lung with left lung hypoplasia</article-title>
          <source>Thorax</source>
          <date>
            <year>1992</year>
          </date>
          <fpage>205</fpage>
          <lpage>6</lpage>
          <issue>3</issue>
          <volume>47</volume>
          <person-group person-group-type="author">
            <name>
              <surname>Ersoz</surname>
              <given-names>A</given-names>
            </name>
            <name>
              <surname>Soncul</surname>
              <given-names>H</given-names>
            </name>
            <name>
              <surname>Gokgoz</surname>
              <given-names>L</given-names>
            </name>
            <name>
              <surname>Kalaycioglu</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Tunaoglu</surname>
              <given-names>S</given-names>
            </name>
            <name>
              <surname>Kaptanoglu</surname>
              <given-names>M</given-names>
            </name>
          </person-group>
        </element-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="translation" id="TRes" xml:lang="es">
    <front-stub>
      <article-categories/>
      <title-group>
        <article-title xml:lang="es">Hipertensi&#243;n pulmonar en lactante asociada a pulm&#243;n en herradura: caso cl&#237;nico</article-title>
      </title-group>
      <abstract xml:lang="es">
        <p>Se presenta un caso de una lactante joven con dificultad respiratoria precoz y la hipertensi&#243;n pulmonar, diagnosticada como una variante de pulm&#243;n en herradura y revisamos literatura acerca de esta rara malformaci&#243;n pulmonar y sus repercusiones cardiacas y hemodin&#225;micas.</p>
      </abstract>
      <kwd-group xml:lang="es">
        <kwd>Cardiopat&#237;as cong&#233;nitas</kwd>
        <kwd>hipertensi&#243;n pulmonar</kwd>
        <kwd>lactante</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>CASO CL&#205;NICO</bold>
      </p>
      <p>
        <fn id="ab-body2">
          <label>
            <bold>Hipertensi&#243;n pulmonar en lactante asociada a pulm&#243;n en herradura: caso cl&#237;nico</bold>
          </label>
          <p>
            <bold>Juliana Rodrigues Neves<sup>I,II,III</sup>; Santiago Raul Arrieta<sup>II</sup>; Catarina V. Cavalcanti<sup>I</sup>; Sandra S. Mattos<sup>III</sup></bold>
          </p>
        </fn>
      </p>
      <p><sup>I</sup>Pronto-Socorro Cardiol&#243;gico de Pernambuco - PROCAPE</p>
      <p><sup>II</sup>Instituto de Medicina Integral Prof. Fernando Figueira - IMIP</p>
      <p><sup>III</sup>Unidade de Cardiologia Materno-Fetal - UCMF, Recife, PE - Brasil</p>
      <p>Correspondencia</p>
      <p>
        <bold>RESUMEM</bold>
      </p>
      <p>Se presenta un caso de una lactante joven con dificultad respiratoria precoz y la hipertensi&#243;n pulmonar, diagnosticada como una variante de pulm&#243;n en herradura y revisamos literatura acerca de esta rara malformaci&#243;n pulmonar y sus repercusiones cardiacas y hemodin&#225;micas. </p>
      <p><bold>Palabras clave:</bold> Cardiopat&#237;as cong&#233;nitas, hipertensi&#243;n pulmonar, lactante.</p>
      <p>
        <bold>Introducci&#243;n</bold>
      </p>
      <p>Pulm&#243;n en herradura es una rara anomal&#237;a cong&#233;nita definida como fusi&#243;n de los segmentos posteroinferiores de los pulmones. La afectaci&#243;n del pulm&#243;n derecho con hipoplasia es m&#225;s frecuente y, en la mayor parte de los casos, se asocia con el s&#237;ndrome de cimitarra. La afectaci&#243;n del pulm&#243;n izquierdo es excepcional y en relaci&#243;n con una peor evoluci&#243;n, as&#237; como la presencia de malformaciones asociadas e hipertensi&#243;n pulmonar<sup>1,2</sup>.</p>
      <p>Se presenta un caso cl&#237;nico de una lactante joven, que se refiere a centro de cardiolog&#237;a pedi&#225;trica para los episodios cian&#243;ticos.</p>
      <p>
        <bold>Caso cl&#237;nico</bold>
      </p>
      <p>Se trata de una lactante de tres meses de vida, sexo femenino, referida a un centro de referencia de cardiolog&#237;a pedi&#225;trica por presentar disnea desde el nacimiento y episodios frecuentes de cianosis. Despu&#233;s del nacimiento, la paciente present&#243; hipoxia leve y dificultad respiratoria en las primeras horas de la vida, lo que requiri&#243; soporte con ventilaci&#243;n mec&#225;nica asistida. Permaneci&#243; en la unidad de cuidados intensivos (UCI) neonatal durante 30 d&#237;as y el reci&#233;n nacido fue dado de alta tras 40 d&#237;as de vida, aunque con dificultad respiratoria y dificultad para la alimentaci&#243;n. A los dos meses de vida tuvo un episodio de cianosis, neumon&#237;a fue diagnosticada en la porci&#243;n izquierda, lo que requirieron soporte ventilatorio por 04 d&#237;as y tratamiento antibi&#243;tico espec&#237;fico. Como no hubo mejora despu&#233;s del tratamiento, persisti&#243; con frecuentes episodios de cianosis, se la remiti&#243; a un servicio terciario en cardiolog&#237;a pedi&#225;trica.</p>
      <p>Al ingreso, estaba con el estado general de compromiso, taquidisneica en grado moderado, con leve cianosis central con la utilizaci&#243;n de cat&#233;ter nasal de ox&#237;geno (O<sub>2</sub>) 3 l/min. Al examen del t&#243;rax, se evidenci&#243; precordio abombado e hiperdinamismo, adem&#225;s de intensa incomodidad respiratoria. A la auscultaci&#243;n card&#237;aca, estaba en ritmo cardiaco regular, taquic&#225;rdico, con hiperfonesis del componente pulmonar de segundo ruido, si soplos. A la auscultaci&#243;n pulmonar, se evidenci&#243; disminuci&#243;n del murmullo vesicular a la izquierda y estertores subcreptantes difusos, adem&#225;s de discreto estridor inspiratorio. Los pulsos eran presentes y sim&#233;tricos. En el abdomen, el h&#237;gado era palpable en el 4,0 cm del reborde costal derecho.</p>
      <p>La paciente fue ingresada en la UCI de Cardiolog&#237;a Pedi&#225;trica para estabilizaci&#243;n hemodin&#225;mica, donde se inici&#243; ventilaci&#243;n no invasiva con una fracci&#243;n de O<sub>2</sub> de 0,5, la furosemida 3,0 mg/kg/d&#237;a y la dobutamina, 5,0 <italic>&#181;</italic>g/kg/min. Evolucion&#243; con estabilizaci&#243;n cl&#237;nica, interrupci&#243;n de soporte ventilatorio e inotr&#243;pico, de modo que, en el 5&#186; d&#237;a tras el ingreso, se encontraba en aire ambiente con taquidisnea leve y manten&#237;a saturaci&#243;n de O<sub>2</sub> alrededor del 96%, en uso de furosemida de 3,0 mg/kg/d&#237;a y digoxina de 0,01 mg/kg/d&#237;a. As&#237; que se inici&#243; la investigaci&#243;n cl&#237;nica.</p>
      <p>La radiograf&#237;a de t&#243;rax mostr&#243; una reducci&#243;n en el volumen del pulm&#243;n izquierdo y desviaci&#243;n de las estructuras del mediastino a este lado (<xref ref-type="fig" rid="es_a18fig01-body2">Figura 1a</xref>). Tra&#237;a la tomograf&#237;a computarizada de t&#243;rax del hospital, cuya evaluaci&#243;n local diagnosticaba hipoplasia de pulm&#243;n izquierdo. Tras un an&#225;lisis, a pesar de la radiograf&#237;a de mala calidad t&#233;cnica, se detect&#243; asimismo una imagen sugerente de la continuidad entre los l&#243;bulos pulmonares inferiores (<xref ref-type="fig" rid="es_a18fig01-body2">Figura 1b</xref>).</p>
      <p content-type="html"><fig id="es_a18fig01-body2"><graphic xlink:href="https://minio.scielo.br/documentstore/1678-4170/XMVQymHs7mPR93HPhgvVv3D/af8da0713eda5fc6253b8982f46d4527bfe70849.jpg"/><graphic xlink:href="1678-4170-abc-96-06-e116-00018-gf01-es.jpg"/></fig>&#13;
&#160;&#13;
</p>
      <p>La ecocardiograf&#237;a transtor&#225;cica identific&#243; un aumento de las c&#225;maras cardiacas derechas con signos de hipertensi&#243;n arterial pulmonar y peque&#241;a comunicaci&#243;n interauricular (CIA) del tipo <italic>ostium secundum.</italic></p>
      <p>Se realiz&#243; cateterismo card&#237;aco que mostr&#243; hipertensi&#243;n arterial pulmonar significativa (<xref ref-type="table" rid="es_a18tab01-body2">Tabla 1</xref>).</p>
      <p content-type="asset">
        <table-wrap id="es_a18tab01-body2">
          <graphic xlink:href="1678-4170-abc-96-06-e116-00018-gt01-es.jpg"/></table-wrap>
      </p>
      <p>A la angiograf&#237;a, se observ&#243; rama de la arteria pulmonar derecha se dirigiendo hacia el istmo del pulm&#243;n izquierdo, sin demostrar claramente el origen de la arteria pulmonar izquierda (pulm&#243;n izquierdo hipopl&#225;sico), con el retorno venoso al hacer esto de forma paralela a la rama arterial hacia el istmo pulmonar, drenando en aur&#237;cula izquierda (<xref ref-type="fig" rid="es_a18fig01-body2">Figuras 1c</xref>, <xref ref-type="fig" rid="es_a18fig01-body2">1d</xref> y <xref ref-type="fig" rid="es_a18fig01-body2">1e</xref>).</p>
      <p>Despu&#233;s de un cateterismo card&#237;aco, el ni&#241;o fue readmitido en la UCI a la sala de recuperaci&#243;n anest&#233;sica y comenz&#243; la terapia con medicamentos para la hipertensi&#243;n pulmonar con sildenafila en las dosis recomendadas. En el tercer d&#237;a despu&#233;s del cateterismo, se encontraba en el aire ambiente, con los medicamentos prescritos previamente y en espera de la dada de alta y traslado a la sala de internaci&#243;n, cuando present&#243; un episodio s&#250;bito de cianosis con bradicardia sinusal que evolucion&#243; hacia asistolia, sin respuesta a las maniobras de reanimaci&#243;n, lo que evolucion&#243; hasta la muerte. El episodio fue interpretado por un m&#233;dico ayudante de guardia como "crisis de hipertensi&#243;n pulmonar."</p>
      <p>Aunque consciente de la gravedad del cuadro e informada acerca de la importancia de la elucidaci&#243;n del diagn&#243;stico, la genitora no autoriz&#243; el estudio anatomopatol&#243;gico, lo que hizo imposible la confirmaci&#243;n anat&#243;mica de los datos aqu&#237; relatados.</p>
      <p>
        <bold>Revisi&#243;n de la literatura y consideraciones</bold>
      </p>
      <p>El pulm&#243;n en herradura se caracteriza por la presencia del istmo de par&#233;nquima pulmonar que se extiende a trav&#233;s de la l&#237;nea media, que conecta las regiones posteriores basales de ambos pulmones, detr&#225;s del coraz&#243;n y por delante de la aorta descendente. Desde su descripci&#243;n en la d&#233;cada de 60 (Spencer, 1962), se relataron 40 casos en la literatura, sobre todo asociados a hipoplasia del pulm&#243;n derecho y a menudo asociadas con el s&#237;ndrome de cimitarra. S&#243;lo hay un caso descrito en un feto de 19 semanas, donde se encontraba el istmo pulmonar en la parte apical de los pulmones, lo que llev&#243; a la reflexi&#243;n sobre el origen embriol&#243;gico de esta malformaci&#243;n<sup>1-3.</sup></p>
      <p>En la mayor&#237;a de los casos, lo sintomatolog&#237;a cl&#237;nica ha comenzado precozmente con problemas pulmonares en ni&#241;os peque&#241;os, beb&#233;s y reci&#233;n nacidos. La dificultad respiratoria frecuente, neumon&#237;as recurrentes y episodios de cianosis son los hallazgos m&#225;s comunes. La hipertensi&#243;n pulmonar se viene relacionando con la evoluci&#243;n precoz de estos pacientes, aunque no sea una regla<sup>1,4.</sup> El s&#237;ndrome de cimitarra est&#225; asociada en el 15% de los casos con el pulm&#243;n en herradura y, a pesar de las similitudes morfol&#243;gicas entre el s&#237;ndrome con o sin esta asociaci&#243;n, su presentaci&#243;n cl&#237;nica es diferente<sup>5</sup>. Los pacientes con pulm&#243;n en herradura presentan m&#225;s temprano una sintomatolog&#237;a evidente y la necesidad precoz de cirug&#237;a, de conformidad a la discusi&#243;n a continuaci&#243;n. Las cardiopat&#237;as cong&#233;nitas ocurren en un 25% de los casos, y el m&#225;s com&#250;n es la comunicaci&#243;n interauricular (50%). Otras lesiones incluyen la comunicaci&#243;n interventricular, la persistencia del canal arterial, la tetralog&#237;a de Fallot, el drenaje an&#243;malo total de venas pulmonares, en el caso descrito recientemente en la literatura nacional, y la coartaci&#243;n de aorta<sup>6,7</sup>. </p>
      <p>Nuestro paciente present&#243; sintomatolog&#237;a en fase muy precoz de la vida, con hipertensi&#243;n pulmonar severa, presentaba asociados la comunicaci&#243;n interauricular y anomal&#237;a de drenaje venoso pulmonar, los factores asociados a mal pron&#243;stico.</p>
      <p>En la radiograf&#237;a de t&#243;rax, se observa hipoplasia de uno de los pulmones y la desviaci&#243;n de las estructuras del mediastino hacia el mismo lado, pero no hay hallazgo t&#237;pico de la malformaci&#243;n<sup>1.</sup> La tomograf&#237;a computarizada de t&#243;rax demuestra hipoplasia pulmonar unilateral con istmo que se extiende hacia m&#225;s all&#225; de la l&#237;nea media. En general, el pulm&#243;n derecho se ve afectado, sin embargo, as&#237; como el caso reportado aqu&#237;, hay casos de afectaci&#243;n del pulm&#243;n izquierdo en la literatura, y se observa todav&#237;a que el istmo se origina en el pulm&#243;n hipopl&#225;sico en todos los casos 2,8. La definici&#243;n del diagn&#243;stico se hace por broncograf&#237;a o angiograf&#237;a cuando se define el suministro bronquial y vascular an&#243;malo para el istmo pulmonar. El cateterismo card&#237;aco, adem&#225;s de demostrar la anatom&#237;a vascular arterial, es una herramienta importante en la evaluaci&#243;n del drenaje venoso del pulm&#243;n afectado, pudiendo haber o no alteraci&#243;n y obstrucci&#243;n en su trayecto, y en el diagn&#243;stico y estudio hemodin&#225;mico de casos asociados con hipertensi&#243;n<sup>1,2</sup>.</p>
      <p>En nuestro caso, la posibilidad diagn&#243;stica se sugiri&#243; s&#243;lo despu&#233;s de cateterismo card&#237;aco, en el que se instituy&#243; el tratamiento con sildenafila en un intento de minimizar los s&#237;ntomas asociados a la hipertensi&#243;n arterial pulmonar, que parece haber contribuido en gran medida al desenlace del caso.</p>
      <p>Cuando sea posible, el tratamiento quir&#250;rgico est&#225; indicado en la presencia de infecciones recurrentes, "cortocircuito" izquierdo significativo (Qp:Qs&gt; 2:1) en la presencia de defectos cardiacos asociados e hipertensi&#243;n pulmonar progresiva. Se debe llevar a cabo la correcci&#243;n de las anomal&#237;as intracardiacas existentes, o si hay infecciones recurrentes, la resecci&#243;n del pulm&#243;n afectado. Debido a la mala evoluci&#243;n de estos pacientes en el posoperatorio, si no hay sintomatolog&#237;a o "cortocircuito" sist&#233;mico-pulmonar, se preconiza el tratamiento conservador<sup>1.</sup></p>
      <p>Aqu&#237; reportamos un caso raro de pulm&#243;n en herradura con afectaci&#243;n del pulm&#243;n izquierdo, el curso cl&#237;nico tempestuoso y la hipertensi&#243;n pulmonar severa. Como no fue posible un estudio anatomopatol&#243;gico del caso en cuesti&#243;n, algunos comentarios se hacen necesarios. Aunque est&#225; descrito de forma aislada como se presenta aqu&#237;, el pulm&#243;n en herradura es com&#250;nmente relacionado con el s&#237;ndrome de cimitarra. Por lo tanto, de forma aislada, el origen de la arteria pulmonar izquierda podr&#237;a caracterizar una forma de anillo vascular y como el <italic>sling</italic> de la arteria pulmonar izquierda, pero sin la compresi&#243;n de la tr&#225;quea distal. Tambi&#233;n se podr&#237;a cuestionar si el curso anormal de esta arteria no ser&#237;a una variaci&#243;n de la rama arterial pulmonar. </p>
      <p>De todos modos, consideramos importante la descripci&#243;n del caso para que el reconocimiento de esta enfermedad sea posible en su fase inicial, ya que presenta una asociaci&#243;n con grados variables de hipertensi&#243;n pulmonar de caracter&#237;sticas evolutivas y, de modo general, un pron&#243;stico precario.</p>
      <p>
        <bold>Potencial Conflicto de Intereses</bold>
      </p>
      <p>Declaro no haber conflicto de intereses pertinentes.</p>
      <p>
        <bold>Fuentes de Financiaci&#243;n</bold>
      </p>
      <p>El presente estudio no tuve fuentes de financiaci&#243;n externas.</p>
      <p>
        <bold>Vinculaci&#243;n Acad&#233;mica</bold>
      </p>
      <p>No hay vinculaci&#243;n de este estudio a programas de postgrado.</p>
      <p>
        <bold>Referencias</bold>
      </p>
    </body>
  </sub-article>
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          <subject>Case Report</subject>
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      <title-group>
        <article-title xml:lang="en">Pulmonary hypertension in infants linked to horseshoe lung: case report</article-title>
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      <abstract xml:lang="en">
        <p>This is the case report of a young infant with early respiratory distress and pulmonary hypertension, diagnosed as a variant of horseshoe lung and we have reviewed the literature to seek information about this rare pulmonary malformation and its cardiac and hemodynamic repercussions.</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>Heart defects, congenital</kwd>
        <kwd>hypertension, pulmonary</kwd>
        <kwd>infant</kwd>
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    <body> - <p><bold>CASE REPORT</bold></p>   <p><fn id="top1-body3"><label><bold>Pulmonary hypertension in infants linked to horseshoe lung: case report</bold></label><p><bold>Juliana Rodrigues Neves<sup>I,II,III</sup>; Santiago Raul Arrieta<sup>II</sup>; Catarina V. Cavalcanti<sup>I</sup>; Sandra S. Mattos<sup>III</sup></bold></p></fn></p>     <p><sup>I</sup>Pronto-Socorro Cardiol&#243;gico de Pernambuco - PROCAPE</p><p><sup>II</sup>Instituto de Medicina Integral Prof. Fernando Figueira - IMIP</p><p><sup>III</sup>Unidade de Cardiologia Materno-Fetal - UCMF, Recife, PE - Brazil</p><p>Mailing address</p>     <p><bold>ABSTRACT</bold></p> <p>This is the case report of a young infant with early respiratory distress and pulmonary hypertension, diagnosed as a variant of horseshoe lung and we have reviewed the literature to seek information about this rare pulmonary malformation and its cardiac and hemodynamic repercussions.</p> <p><bold>Keywords: </bold>Heart defects, congenital; hypertension, pulmonary; infant</p>     <p><bold>Introduction</bold></p> <p>Horseshoe lung is a rare congenital anomaly defined as a fusion of the lower posterior segments of the lungs. The involvement of the right lung with hypoplasia is more common and in most cases, it is associated with the scimitar syndrome. The involvement of the left lung is exceptional and related to worse outcomes, as well as the presence of associated cardiac malformations and pulmonary hypertension<sup>1,2</sup>.</p> <p>We report the case of a young infant referred to pediatric cardiology center due to cyanotic episodes.</p>   <p><bold>Case Report</bold></p> <p>This article reports the case of an infant at three months of life, female, referred to a referral center of pediatric cardiology for presenting dyspnea since birth and frequent episodes of cyanosis. After birth, the patient developed respiratory distress and mild hypoxia in the early hours of life, requiring support with mechanical ventilation. The patient remained in the neonatal intensive care unit (ICU) for 30 days and was discharged after 40 days of life still with respiratory distress and feeding difficulty. At two months of life, she had an episode of cyanosis, pneumonia was diagnosed on the left, requiring ventilatory support for 04 days and specific antibiotic therapy. As there was no improvement after therapy, persisting with frequent episodes of cyanosis, she was referred to a tertiary pediatric cardiology service.</p> <p>Upon admission, she had an impaired general health status, was moderately tachydyspneic, with mild central cyanosis using a nasal oxygen catheter (O<sub>2</sub>) 3 l/min. Upon inspection of the chest, the patient had precordial bulge and hyperdynamism and intense respiratory distress. Upon cardiac auscultation, the patient was in regular cardiac rhythm, tachycardic, with accentuation of the pulmonic component of the second heart sound, without murmurs. Upon lung auscultation, there was evidence of decreased vesicular murmur on the left and diffuse subcrepitant rales, and mild inspiratory stridor. Pulses were present and symmetrical. In the abdomen, liver was palpable at 4.0 cm from the right costal edge.</p> <p>The patient was admitted to the cardiopediatric ICU for hemodynamic stabilization where noninvasive ventilation was initiated with a fraction of O<sub>2</sub> of 0.5, furosemide 3.0 mg/kg/day and dobutamine, 5.0 &#181;g/kg/min. Evolved with clinical stabilization, weaning from inotropic and ventilatory support, so that in the fifth day after admission, she was in ambient air with mild tachydyspnea, keeping O<sub>2</sub> saturation around 96.0% using furosemide 3.0 mg/kg/day and digoxin 0.01 mg/kg/day. Clinical research was then initiated.</p> <p>Chest radiography showed a reduced volume of the left lung and deviation of mediastinal structures to this side (<xref ref-type="fig" rid="en_a18fig01-body3">Figure 1a</xref>). The patient had, from the source hospital, computed tomography, whose local evaluation diagnosed hypoplastic left lung. Subsequent analysis, despite the poor technical quality of the test, also detected an image suggesting continuity between the lower lung lobes (<xref ref-type="fig" rid="en_a18fig01-body3">Figure 1b</xref>).</p><p content-type="html"><fig id="en_a18fig01-body3"><graphic xlink:href="https://minio.scielo.br/documentstore/1678-4170/XMVQymHs7mPR93HPhgvVv3D/91614c3b32c5d8583ca4d5ac5a3870657e9e6f87.jpg"/><graphic xlink:href="1678-4170-abc-96-06-e116-00018-gf01-en.jpg"/></fig>&#13;
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</p> <p>Transthoracic echocardiography identified an increase of right heart chambers with signs of pulmonary arterial hypertension and small ostium secundum atrial septal defect (ASD).</p> <p>Cardiac catheterization revealed significant pulmonary hypertension (<xref ref-type="table" rid="en_a18tab01m-body3">Table 1</xref>).</p><p content-type="asset"><table-wrap id="en_a18tab01m-body3"><graphic xlink:href="1678-4170-abc-96-06-e116-00018-gt01-en.jpg"/></table-wrap></p> <p>On angiography, we observed right pulmonary artery branch going to the isthmus of the left lung, and is did not clearly demonstrated the origin of the left pulmonary artery (hypoplastic left lung), with venous return parallel to this pulmonary artery branch to the pulmonary isthmus draining into the left atrium (<xref ref-type="fig" rid="en_a18fig01-body3">Figures 1c</xref>, <xref ref-type="fig" rid="en_a18fig01-body3">1d</xref> and <xref ref-type="fig" rid="en_a18fig01-body3">1e</xref>).</p> <p>After cardiac catheterization, the child was readmitted to the ICU for recovery room and began drug therapy for pulmonary hypertension with sildenafil at the doses recommended. On the third day after catheterization, she was in ambient air, with the previously prescribed medications, awaiting discharge to the ward, when she had a sudden onset of cyanosis with sinus bradycardia progressing to asystole unresponsive to resuscitation, progressing to death. The episode was interpreted by an assistant on duty as "pulmonary hypertension crisis".</p> <p>Although aware of the severity of the condition, and informed about the importance of laboratory diagnosis, the mother did not authorize anatomopathological study, which made it impossible to confirm the anatomy of the data reported here.</p>   <p><bold>Literature review and considerations</bold></p> <p>Horseshoe lung is characterized by the presence of the isthmus of pulmonary parenchyma that extends across the midline, connecting the posterior basal regions of both lungs, behind the heart and anterior to the descending aorta. Since its description in the 60s (Spencer, 1962) about 40 cases were reported in the world literature, mostly associated with hypoplastic right lung and often associated with scimitar syndrome. There is only one case described in a fetus of 19 weeks, where the pulmonary isthmus was located in the apical portion of the lungs, which led to reflections about the embryological origin of this malformation<sup>1-3</sup>.</p> <p>In most cases, the clinical symptoms began early with lung problems in young children, infants and neonates. Frequent respiratory distress, recurrent pneumonia and episodes of cyanosis are the most common findings. Pulmonary hypertension has been implicated in the early evolution of such patients, although it is not a rule<sup>1,4</sup>. The scimitar syndrome is associated in 15.0% of the cases with horseshoe lung. Despite the morphological similarities between the syndrome with or without this association, its clinical presentation is different<sup>5</sup>. Patients with horseshoe lung have obvious symptoms early and early need for surgery, as discussed below. Congenital heart defects occur in 25.0% of the cases; the most common one is the atrial septal defect (50.0%). Other lesions include ventricular septal defect, patent ductus arteriosus, tetralogy of Fallot, total anomalous pulmonary veins, in a case described recently in the national literature, and coarctation of the aorta<sup>6,7</sup>.</p> <p>Our patient presented symptoms very early in life, with severe pulmonary hypertension, associated atrial septal defect and anomalous pulmonary venous drainage, factors related to poor prognosis.</p> <p>In chest radiography there is hypoplasia of one lung and deviation of mediastinal structures to the same side, but no typical finding of malformation<sup>1</sup>. Chest computed tomography demonstrates unilateral pulmonary hypoplasia with isthmus extending beyond the midline. Generally, the right lung is affected. However, as in the case reported here, cases of involvement of the left lung have been described. Also, it has been observed that the isthmus originates from the hypoplastic lung in all cases<sup>2,8</sup>. The definition of the diagnosis is made by angiography or bronchography when the bronchial and anomalous vascular supply to the pulmonary isthmus is defined. Cardiac catheterization, in addition to demonstrating the arterial vascular anatomy, is an important tool in the evaluation of venous drainage of the affected lung, and there may be or not alteration and obstruction in its path, and in the diagnosis and hemodynamic study of cases associated with pulmonary hypertension<sup>1,2</sup>.</p> <p>In our case, the diagnostic possibility was suggested only after cardiac catheterization, where treatment with Sildenafil was instituted in an attempt to minimize symptoms related to pulmonary hypertension, which appears to have greatly contributed to the outcome of the case.</p> <p>When possible, surgical treatment is indicated in the presence of recurrent infections, significant left-right short-circuiting (Qp:Qs &gt; 2:1) in the presence of associated cardiac defects and progressive pulmonary hypertension. The correction of existing intracardiac anomalies is strongly recommended, or if there is recurrent infection, resection of the affected lung. Due to the poor prognosis of these patients postoperatively, if there are no symptoms or significant systemic-pulmonary short-circuiting, conservative treatment is recommended<sup>1</sup>.</p> <p>Here, we report a rare case of horseshoe lung with involvement of the left lung, stormy clinical course and severe pulmonary hypertension. Since it was not possible to perform an anatomopathological study of the case, some comments are needed. Though described in isolation as presented here, horseshoe lung is commonly related to the scimitar syndrome. Thus, in isolation, the aberrant origin of the left pulmonary artery could characterize a form of vascular ring, such as the sling of the left pulmonary artery, but without compression of the distal trachea. We could also question whether the abnormal course of this artery would not be a variation of the pulmonary arterial branch.</p> <p>Anyway, we consider important to describe the case so that the recognition of this disease be possible in its early stage, as it presents an association with variable degrees of pulmonary hypertension of an evolutive character and, in general, poor prognosis.</p> <p><bold>Potential Conflict of Interest</bold></p> <p>No potential conflict of interest relevant to this article was reported.</p> <p><bold>Sources of Funding</bold></p> <p>There were no external funding sources for this study.</p> <p><bold>Study Association</bold></p> <p>This study is not associated with any post-graduation program.</p>   <p><bold>References</bold></p>        </body>
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