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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">7qMnz6TVGx83ypjvBYCdscP</article-id>
      <article-id specific-use="scielo-v2" pub-id-type="publisher-id">S0066-782X2026000504206</article-id>
      <article-id pub-id-type="other">04206</article-id>
      <article-id pub-id-type="doi">10.36660/abc.20260186</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Carta ao Editor</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Desenvolvimento de Modelos de Cardiopatia Cong&#234;nita Impressos em 3D Usando Fluxo de Trabalho Vi&#225;vel e de Baixo Custo</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0009-0002-5881-2709</contrib-id>
          <name>
            <surname>Daungsupawong</surname>
            <given-names>Hinpetch</given-names>
          </name>
          <xref ref-type="aff" rid="aff1">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c1"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Wiwanitkit</surname>
            <given-names>Viroj</given-names>
          </name>
          <xref ref-type="aff" rid="aff2">
            <sup>2</sup>
          </xref>
        </contrib>
        <aff id="aff1">
          <label>1</label>
          <institution content-type="orgname">Private Academic Consulant</institution>
          <addr-line>
            <named-content content-type="city">Vientiane</named-content>
          </addr-line>
          <country country="LA">Laos</country>
          <institution content-type="original">Private Academic Consulant, Vientiane - Laos</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution content-type="orgname">Saveetha Institute of Medical and Technical Sciences</institution>
          <institution content-type="orgdiv1">Saveetha Dental College</institution>
          <addr-line>
            <named-content content-type="city">Chennai</named-content>
          </addr-line>
          <country country="IN">&#205;ndia</country>
          <institution content-type="original">Saveetha Institute of Medical and Technical Sciences (Deemed to be University) Saveetha Dental College, Chennai &#8211; &#205;ndia</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c1"><label>Correspond&#234;ncia:</label><bold>Hinpetch Daungsupawong</bold> &#8226; Private Academic Consulant Lak, 42 Phonhong Vientiane, 10000, Laos E-mail: <email>hinpetchdaung@gmail.com</email> </corresp>
      </author-notes>
      <pub-date date-type="pub" publication-format="electronic">
        <day>07</day>
        <month>08</month>
        <year>2026</year>
      </pub-date>
      <pub-date date-type="collection" publication-format="electronic">
        <year>2026</year>
      </pub-date>
      <volume>123</volume>
      <issue>5</issue>
      <elocation-id>e20260186</elocation-id>
      <history>
        <date date-type="received">
          <day>05</day>
          <month>03</month>
          <year>2026</year>
        </date>
        <date date-type="rev-recd">
          <day>13</day>
          <month>03</month>
          <year>2026</year>
        </date>
        <date date-type="accepted">
          <day>13</day>
          <month>03</month>
          <year>2026</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/" xml:lang="en">
          <license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
        </license>
      </permissions>
      <related-article related-article-type="article" id="r1" xlink:href="10.36660/abc.20250419" ext-link-type="doi"/>
      <related-article related-article-type="reply" id="r2" xlink:href="10.36660/abc.20260186" ext-link-type="doi"/>
      <kwd-group xml:lang="pt">
        <title>Palavras-chave</title>
        <kwd>Impress&#227;o Tridimensional</kwd>
        <kwd>Cardiologia</kwd>
      </kwd-group>
      <counts>
        <fig-count count="0"/>
        <table-count count="0"/>
        <equation-count count="0"/>
        <ref-count count="3"/>
      </counts>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>Prezado Editor,</bold>
    </p>
    <p>A publica&#231;&#227;o intitulada "Desenvolvimento de Modelos de Cardiopatias Cong&#234;nitas em Impress&#227;o 3D utilizando Metodologia de Baixo Custo &#8211; Uma Potencial Ferramenta para Aprimorar o Ensino da Cardiologia Pedi&#225;trica<sup><xref ref-type="bibr" rid="B1">1</xref></sup>" &#233; aqui discutida. Este estudo apresenta um conceito interessante de utiliza&#231;&#227;o da tecnologia de impress&#227;o 3D para criar modelos de baixo custo de cardiopatias cong&#234;nitas, uma abordagem potencial para apoiar o aprendizado anat&#244;mico e fisiopatol&#243;gico. No entanto, uma limita&#231;&#227;o significativa do estudo reside na sua avalia&#231;&#227;o de resultados, que se baseia principalmente em opini&#245;es subjetivas dos participantes. Foram utilizados apenas question&#225;rios de satisfa&#231;&#227;o de m&#233;dicos residentes, sem medidas quantitativas de desempenho de aprendizagem, como pontua&#231;&#245;es pr&#233; e p&#243;s-teste ou compara&#231;&#245;es com outros recursos did&#225;ticos, como imagens 2D ou modelos digitais.</p>
    <p>Al&#233;m disso, o tamanho da amostra de avaliadores n&#227;o foi claramente especificado, o que pode limitar a confiabilidade das conclus&#245;es sobre a efic&#225;cia educacional. Ademais, a classifica&#231;&#227;o de "100% de concord&#226;ncia" em diversas quest&#245;es pode refletir vi&#233;s de desejabilidade social.</p>
    <p>Metodologicamente, existem limita&#231;&#245;es quanto &#224; validade anat&#244;mica do modelo. O processo de modelagem utiliza dados de tomografia computadorizada combinados com dados de v&#225;lvulas card&#237;acas obtidos por ecocardiografia, utilizando t&#233;cnicas de mapeamento de altura, o que pode levar a erros devido &#224; integra&#231;&#227;o de dados de duas fontes de imagem com resolu&#231;&#245;es e &#226;ngulos de vis&#227;o diferentes. Al&#233;m disso, o uso de impressoras 3D de mesa e materiais de baixo custo pode afetar a resolu&#231;&#227;o estrutural, particularmente para pequenas estruturas como folhetos valvares ou trab&#233;culas. A aus&#234;ncia de indicadores quantitativos quanto &#224; precis&#227;o dimensional ou compara&#231;&#227;o com os dados de imagem originais, juntamente com an&#225;lises estat&#237;sticas ou testes de diferen&#231;as entre modelos ou grupos de aprendizes, limita a interpreta&#231;&#227;o dos resultados apenas a n&#237;veis descritivos.</p>
    <p>Uma reinterpreta&#231;&#227;o dos resultados do estudo sugere que os modelos 3D de baixo custo s&#227;o valiosos n&#227;o apenas pelo seu realismo anat&#244;mico, mas tamb&#233;m desempenham um papel crucial como ferramenta para aumentar o envolvimento na aprendizagem. Esse envolvimento pode ser um fator-chave na percep&#231;&#227;o dos alunos sobre a compreens&#227;o das estruturas espaciais. A cria&#231;&#227;o de um conjunto abrangente de modelos que cubram m&#250;ltiplos tipos de cardiopatias cong&#234;nitas tamb&#233;m pode facilitar a aprendizagem comparativa da morfologia, ben&#233;fica para o desenvolvimento do racioc&#237;nio cl&#237;nico. No entanto, essa efic&#225;cia deve ser investigada mais a fundo por meio de estudos experimentais que comparem esses modelos a m&#233;todos de ensino padr&#227;o, como a visualiza&#231;&#227;o digital em 3D ou a realidade virtual.</p>
    <p>Quest&#245;es para discuss&#227;o futura incluem: Os modelos 3D de baixo custo superam a m&#237;dia digital a longo prazo? Qual &#233; a resolu&#231;&#227;o m&#237;nima necess&#225;ria para que os modelos mantenham seu valor educacional? Qual a efic&#225;cia do uso desses modelos na comunica&#231;&#227;o com pacientes ou familiares? Al&#233;m disso, a cria&#231;&#227;o de um banco de dados de modelos de cardiopatia cong&#234;nita de c&#243;digo aberto poderia ajudar a reduzir as disparidades educacionais entre institui&#231;&#245;es? Essa ser&#225; uma dire&#231;&#227;o fundamental para o desenvolvimento futuro dessa tecnologia.</p>
  </body>
  <back>
    <ref-list>
      <title>Refer&#234;ncias</title>
      <ref id="B1">
        <label>1</label>
        <element-citation publication-type="journal">
          <person-group person-group-type="author">
            <name>
              <surname>Cajueiro</surname>
              <given-names>FCM</given-names>
            </name>
            <name>
              <surname>Croti</surname>
              <given-names>UA</given-names>
            </name>
            <name>
              <surname>Amorim</surname>
              <given-names>RF</given-names>
              <suffix>Jr</suffix>
            </name>
            <name>
              <surname>Cardoso</surname>
              <given-names>MRR</given-names>
            </name>
            <name>
              <surname>Costa</surname>
              <given-names>CH</given-names>
            </name>
            <name>
              <surname>Marchi</surname>
              <given-names>CH</given-names>
            </name>
            <etal/>
          </person-group>
          <article-title>Development of 3D-Printed Congenital Heart Disease Models Using Feasible Low-Cost Workflow - A Potential Tool to Improve Pediatric Cardiology Education</article-title>
          <source>Arq Bras Cardiol</source>
          <year>2026</year>
          <volume>123</volume>
          <issue>1</issue>
          <elocation-id>e20250419</elocation-id>
          <pub-id pub-id-type="doi">10.36660/abc.20250419</pub-id>
        </element-citation>
        <mixed-citation>1 Cajueiro FCM, Croti UA, Amorim RF Jr, Cardoso MRR, Costa CH, Marchi CH, et al. Development of 3D-Printed Congenital Heart Disease Models Using Feasible Low-Cost Workflow - A Potential Tool to Improve Pediatric Cardiology Education. Arq Bras Cardiol. 2026;123(1):e20250419. doi: 10.36660/abc.20250419.</mixed-citation>
      </ref>
    </ref-list>
  </back>
  <sub-article article-type="reply" id="R01" xml:lang="pt">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Carta ao Editor</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Carta-resposta</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-6465-8798</contrib-id>
          <name>
            <surname>Cajueiro</surname>
            <given-names>Francisco Candido Monteiro</given-names>
          </name>
          <xref ref-type="aff" rid="aff3">
            <sup>1</sup>
          </xref>
        </contrib>
        <aff id="aff3">
          <label>1</label>
          <institution content-type="orgname">Universidade de Pernambuco</institution>
          <addr-line>
            <named-content content-type="city">Recife</named-content>
            <named-content content-type="state">PE</named-content>
          </addr-line>
          <country country="BR">Brasil</country>
          <institution content-type="original">Universidade de Pernambuco, Recife, PE &#8211; Brasil</institution>
        </aff>
      </contrib-group>
    </front-stub>
    <body>
      <p>
        <bold>Prezado Editor,</bold>
      </p>
      <p>Agradecemos ao autor pelo interesse em nosso trabalho e pelos coment&#225;rios pertinentes sobre nosso estudo acerca do desenvolvimento de modelos de cardiopatia cong&#234;nita (CC) impressos em tr&#234;s dimens&#245;es (3D) de baixo custo.</p>
      <p>Nosso estudo foi concebido com um objetivo espec&#237;fico e claramente definido: descrever um fluxo de trabalho vi&#225;vel, reproduz&#237;vel e de baixo custo para o desenvolvimento de modelos de cardiopatia cong&#234;nita impressos em 3D e fornecer um recurso educacional compartilh&#225;vel. Nesse contexto, o trabalho foi intencionalmente projetado como um estudo descritivo, no estilo "fa&#231;a voc&#234; mesmo", com foco na acessibilidade e na implementa&#231;&#227;o pr&#225;tica, em vez de valida&#231;&#227;o quantitativa ou an&#225;lise comparativa de desempenho. Acreditamos que essa distin&#231;&#227;o seja essencial para a interpreta&#231;&#227;o adequada de nossos resultados.</p>
      <p>O crescente interesse na impress&#227;o 3D em cardiologia levou ao desenvolvimento de modelos altamente sofisticados com excelente fidelidade anat&#244;mica, frequentemente utilizando softwares avan&#231;ados, integra&#231;&#227;o de imagens multimodais e materiais de alto custo. Embora essas abordagens representem avan&#231;os importantes, podem n&#227;o ser facilmente acess&#237;veis em muitas institui&#231;&#245;es, particularmente em pa&#237;ses de baixa e m&#233;dia renda. Por esse motivo, estrat&#233;gias de baixo custo t&#234;m sido cada vez mais exploradas, demonstrando que fluxos de trabalho simplificados, baseados em softwares de c&#243;digo aberto e impress&#227;o 3D de mesa, ainda podem produzir modelos com significativo valor educacional.</p>
      <p>Nesse contexto, as escolhas metodol&#243;gicas adotadas em nosso estudo (incluindo o uso de hardware de baixo custo, representa&#231;&#245;es anat&#244;micas simplificadas e t&#233;cnicas alternativas para modelagem de v&#225;lvulas) foram deliberadas e alinhadas com o prop&#243;sito dos modelos. Conforme explicitamente declarado no manuscrito, esses modelos n&#227;o foram projetados para tomada de decis&#245;es cl&#237;nicas ou planejamento cir&#250;rgico, mas sim como ferramentas educacionais destinadas a aprimorar a compreens&#227;o espacial, a comunica&#231;&#227;o e o engajamento entre alunos e o p&#250;blico n&#227;o especializado.</p>
      <p>A estrat&#233;gia de avalia&#231;&#227;o tamb&#233;m foi alinhada a esse objetivo. A avalia&#231;&#227;o qualitativa, realizada por m&#233;dicos especialistas e residentes, foi utilizada para explorar a usabilidade, a clareza e os benef&#237;cios educacionais percebidos. Embora reconhe&#231;amos as limita&#231;&#245;es inerentes &#224; avalia&#231;&#227;o subjetiva e o potencial de vi&#233;s, esses aspectos foram considerados e discutidos no manuscrito. Em est&#225;gios iniciais de inova&#231;&#227;o educacional, essas abordagens fornecem informa&#231;&#245;es valiosas sobre a experi&#234;ncia do usu&#225;rio e a aplicabilidade no mundo real.</p>
      <p>Reconhecemos tamb&#233;m que estudos adicionais que incorporem valida&#231;&#227;o quantitativa, delineamentos comparativos e avalia&#231;&#227;o a longo prazo da reten&#231;&#227;o de conhecimento fortaleceriam ainda mais a base de evid&#234;ncias nesta &#225;rea. Essas dire&#231;&#245;es representam importantes oportunidades para pesquisas futuras e estavam al&#233;m do escopo do presente estudo, que se concentrou principalmente na viabilidade e acessibilidade.</p>
      <p>Uma importante contribui&#231;&#227;o do nosso trabalho &#233; o compartilhamento aberto dos modelos desenvolvidos por meio de uma plataforma de acesso livre (<ext-link ext-link-type="uri" xlink:href="https://sites.google.com/view/3dpequenoscoracoes">https://sites.google.com/view/3dpequenoscoracoes</ext-link>), permitindo a replica&#231;&#227;o, adapta&#231;&#227;o e dissemina&#231;&#227;o em diferentes contextos. Acreditamos que essa abordagem pode ajudar a ampliar o acesso a ferramentas educacionais em cardiologia cong&#234;nita, principalmente em locais com recursos limitados, al&#233;m de contribuir para a democratiza&#231;&#227;o mais ampla de tecnologias educacionais avan&#231;adas em medicina cardiovascular.</p>
      <p>Al&#233;m disso, gostar&#237;amos de destacar um breve editorial recente que aborda o papel da impress&#227;o 3D de baixo custo na educa&#231;&#227;o sobre cardiopatias cong&#234;nitas, o qual oferece uma perspectiva ponderada e equilibrada sobre v&#225;rias das quest&#245;es aqui discutidas.<sup><xref ref-type="bibr" rid="B2">1</xref></sup> Tamb&#233;m recomendamos aos leitores interessados uma entrevista em v&#237;deo relacionada, que explora mais a fundo as motiva&#231;&#245;es e os aspectos pr&#225;ticos dessa iniciativa.<sup><xref ref-type="bibr" rid="B3">2</xref></sup></p>
      <p>Em resumo, nosso estudo visa complementar os avan&#231;os existentes na impress&#227;o 3D, demonstrando que recursos educacionais relevantes podem ser desenvolvidos utilizando m&#233;todos acess&#237;veis. Agradecemos a oportunidade de esclarecer esses pontos e de contribuir para o debate em curso sobre estrat&#233;gias inovadoras e inclusivas na educa&#231;&#227;o sobre cardiopatias cong&#234;nitas.</p>
    </body>
    <back>
      <ref-list>
        <title>Refer&#234;ncias</title>
        <ref id="B2">
          <label>1</label>
          <element-citation publication-type="journal">
            <person-group person-group-type="author">
              <name>
                <surname>Ramos</surname>
                <given-names>V</given-names>
              </name>
            </person-group>
            <article-title>The Role of Low-Cost 3D Printing for Education in Congenital Heart Diseases</article-title>
            <source>Arq Bras Cardiol</source>
            <year>2026</year>
            <volume>123</volume>
            <issue>1</issue>
            <elocation-id>e20250805</elocation-id>
            <pub-id pub-id-type="doi">10.36660/abc.20250805</pub-id>
          </element-citation>
          <mixed-citation>1 Ramos V. The Role of Low-Cost 3D Printing for Education in Congenital Heart Diseases. Arq Bras Cardiol. 2026;123(1):e20250805. doi: 10.36660/abc.20250805.</mixed-citation>
        </ref>
        <ref id="B3">
          <label>2</label>
          <element-citation publication-type="book">
            <person-group person-group-type="author">
              <collab>ABC Cardiol</collab>
            </person-group>
            <source>ABC Spotlight &#8211; Dr. Francisco Cajueiro [Internet]</source>
            <publisher-loc>Rio de Janeiro</publisher-loc>
            <publisher-name>ABC Cardiol</publisher-name>
            <year>2026</year>
            <date-in-citation content-type="access-date">[cited 2026 May 12]</date-in-citation>
            <comment>Available from: <ext-link ext-link-type="uri" xlink:href="https://abccardiol.org/video/abc-spotlight-dr-francisco-cajueiro/">https://abccardiol.org/video/abc-spotlight-dr-francisco-cajueiro/</ext-link> </comment>
          </element-citation>
          <mixed-citation>2 ABC Cardiol. ABC Spotlight &#8211; Dr. Francisco Cajueiro [Internet]. Rio de Janeiro: ABC Cardiol; 2026 [cited 2026 May 12]. Available from: <ext-link ext-link-type="uri" xlink:href="https://abccardiol.org/video/abc-spotlight-dr-francisco-cajueiro/">https://abccardiol.org/video/abc-spotlight-dr-francisco-cajueiro/</ext-link>.</mixed-citation>
        </ref>
      </ref-list>
    </back>
  </sub-article>
  <sub-article article-type="translation" id="S01" xml:lang="en">
    <front-stub>
      <article-id pub-id-type="doi">10.36660/abc.20260186i</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Letter to the Editor</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Development of 3D-Printed Congenital Heart Disease Models Using Feasible Low-Cost Workflow</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0009-0002-5881-2709</contrib-id>
          <name>
            <surname>Daungsupawong</surname>
            <given-names>Hinpetch</given-names>
          </name>
          <xref ref-type="aff" rid="aff4">
            <sup>1</sup>
          </xref>
          <xref ref-type="corresp" rid="c2"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Wiwanitkit</surname>
            <given-names>Viroj</given-names>
          </name>
          <xref ref-type="aff" rid="aff5">
            <sup>2</sup>
          </xref>
        </contrib>
        <aff id="aff4">
          <label>1</label>
          <addr-line>
            <named-content content-type="city">Vientiane</named-content>
          </addr-line>
          <country country="LA">Laos</country>
          <institution content-type="original">Private Academic Consulant, Vientiane - Laos</institution>
        </aff>
        <aff id="aff5">
          <label>2</label>
          <addr-line>
            <named-content content-type="city">Chennai</named-content>
          </addr-line>
          <country country="IN">India</country>
          <institution content-type="original">Saveetha Institute of Medical and Technical Sciences (Deemed to be University) Saveetha Dental College, Chennai &#8211; India</institution>
        </aff>
      </contrib-group>
      <author-notes>
        <corresp id="c2"><label>Mailing Address:</label><bold>Hinpetch Daungsupawong</bold> &#8226; Private Academic Consulant Lak, 42 Phonhong Vientiane, <postal-code>10000</postal-code>, Laos E-mail: <email>hinpetchdaung@gmail.com</email> </corresp>
      </author-notes>
      <related-article related-article-type="article" id="r3" xlink:href="10.36660/abc.20250419i" ext-link-type="doi"/>
      <related-article related-article-type="reply" id="r4" xlink:href="10.36660/abc.20260186i" ext-link-type="doi"/>
      <kwd-group xml:lang="en">
        <title>Keywords</title>
        <kwd>Three-Dimensional Printing</kwd>
        <kwd>Cardiology</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>Dear Editor</bold>
      </p>
      <p>The publication on "Development of 3D-Printed Congenital Heart Disease Models Using Feasible Low-Cost Workflow - A Potential Tool to Improve Pediatric Cardiology Education<sup><xref ref-type="bibr" rid="B1">1</xref></sup>" is hereby discussed. This study presents an interesting concept of using 3D printing technology to create low-cost models of congenital heart disease, a potential approach to support anatomical and pathophysiological learning. However, a significant limitation of the study lies in its evaluation of outcomes, which relies primarily on subjective opinions from participants. Only resident physician satisfaction questionnaires were used, without quantitative learning achievement measures such as pre- and post-test scores or comparisons with other teaching aids like 2D images or digital models. Furthermore, the sample size of the evaluators was not clearly specified, potentially limiting the reliability of conclusions regarding educational effectiveness. Additionally, the "100% agreement" rating on several issues may reflect social desirability bias.</p>
      <p>Methodologically, there are limitations regarding the anatomical validity of the model. The modeling process uses data from CT scans combined with heart valve data from echocardiography using height mapping techniques, which may lead to errors due to the integration of data from two image sources with different resolutions and viewing angles. Moreover, the use of desktop 3D printers and low-cost materials may affect structural resolution, particularly for small structures such as valve leaflets or trabeculations. The lack of quantitative indicators regarding dimensional accuracy or comparison with original imaging data, along with statistical analysis or testing for differences between models or learner groups, limits the interpretation of the results to descriptive levels only.</p>
      <p>A reinterpretation of the study results suggests that low-cost 3D models are valuable not only for their anatomical realism but also play a crucial role as a tool for enhancing learning engagement. This engagement may be a key factor in learners&#8217; perceived understanding of spatial structures. Creating a comprehensive set of models covering multiple CHD types may also facilitate comparative morphology learning, beneficial for developing clinical thinking skills. However, this effectiveness should be further investigated through experimental study designs comparing these models to standard teaching methods, such as digital 3D visualization or virtual reality.</p>
      <p>Future discussion questions include: Do low-cost 3D models outperform digital media in the long term? What is the minimum resolution required for models to maintain educational value? How effectively can the use of these models impact communication with patients or families? Furthermore, could the creation of an open-source CHD model database help reduce educational disparities between institutions? This will be a key direction for the future development of this technology.</p>
    </body>
  </sub-article>
  <sub-article article-type="reply" id="R02" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Letter to the Editor</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Reply</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <contrib-id contrib-id-type="orcid">0000-0002-6465-8798</contrib-id>
          <name>
            <surname>Cajueiro</surname>
            <given-names>Francisco Candido Monteiro</given-names>
          </name>
          <xref ref-type="aff" rid="aff6">
            <sup>1</sup>
          </xref>
        </contrib>
        <aff id="aff6">
          <label>1</label>
          <addr-line>
            <named-content content-type="city">Recife</named-content>
            <named-content content-type="state">PE</named-content>
          </addr-line>
          <country country="BR">Brazil</country>
          <institution content-type="original">Universidade de Pernambuco, Recife, PE &#8211; Brazil</institution>
        </aff>
      </contrib-group>
    </front-stub>
    <body>
      <p>
        <bold>Dear Editor,</bold>
      </p>
      <p>We thank the author for their interest in our work and for the thoughtful comments regarding our study on the development of low-cost three-dimensional (3D) printed congenital heart disease (CHD) models.</p>
      <p>Our study was conceived with a specific and clearly defined objective: to describe a feasible, reproducible, and low-cost workflow for the development of 3D-printed CHD models and to provide a shareable educational resource. In this context, the work was intentionally designed as a descriptive, "do-it-yourself"&#8211;style study, focused on accessibility and practical implementation rather than on quantitative validation or comparative performance analysis. We believe this distinction is essential for the appropriate interpretation of our findings.</p>
      <p>The growing interest in 3D printing in cardiology has led to the development of highly sophisticated models with excellent anatomical fidelity, often relying on advanced software, multimodal imaging integration, and high-cost materials. While these approaches represent important advances, they may not be readily accessible in many institutions, particularly in low- and middle-income settings. For this reason, cost-effective strategies have been increasingly explored, demonstrating that simplified workflows based on open-source software and desktop 3D printing can still produce models with meaningful educational value.</p>
      <p>Within this framework, the methodological choices adopted in our study (including the use of low-cost hardware, simplified anatomical representations, and alternative techniques for valve modeling) were deliberate and aligned with the intended purpose of the models. As explicitly stated in the manuscript, these models were not designed for clinical decision-making or surgical planning, but rather as educational tools aimed at improving spatial understanding, communication, and engagement among learners and non-specialist audiences.</p>
      <p>The evaluation strategy was similarly aligned with this objective. Qualitative assessment by both expert physicians and trainees was used to explore usability, clarity, and perceived educational benefits. While we acknowledge the inherent limitations of subjective evaluation and the potential for bias, these aspects were recognized and discussed in the manuscript. In early-stage educational innovation, such approaches provide valuable insight into user experience and real-world applicability.</p>
      <p>We also recognize that additional studies incorporating quantitative validation, comparative designs, and long-term assessment of knowledge retention would further strengthen the evidence base in this field. These directions represent important opportunities for future research and were beyond the scope of the present study, which was primarily focused on feasibility and accessibility.</p>
      <p>An important contribution of our work is the open sharing of the developed models through a freely accessible platform (<ext-link ext-link-type="uri" xlink:href="https://sites.google.com/view/3dpequenoscoracoes">https://sites.google.com/view/3dpequenoscoracoes</ext-link>), allowing replication, adaptation, and dissemination across different contexts. We believe that this approach may help expand access to educational tools in congenital cardiology, particularly in resource-limited settings, while contributing to the broader democratization of advanced educational technologies in cardiovascular medicine.</p>
      <p>In addition, we would like to highlight a recent short editorial addressing the role of low-cost 3D printing in CHD education, which provides a thoughtful and balanced perspective on several of the issues discussed here.<sup><xref ref-type="bibr" rid="B2">1</xref></sup> We also refer interested readers to a related videocast interview that further explores the motivations and practical aspects of this initiative.<sup><xref ref-type="bibr" rid="B3">2</xref></sup></p>
      <p>In summary, our study aims to complement existing advances in 3D printing by demonstrating that meaningful educational resources can be developed using accessible methods. We appreciate the opportunity to clarify these points and to contribute to the ongoing discussion on innovative and inclusive strategies in congenital heart disease education.</p>
    </body>
  </sub-article>
</article>
