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How to repair a baby’s broken heart

Healthy heart circulation

Deoxygenated blood (blue) arrives in the heart’s right atrium from two veins — the superior and inferior vena cava and is then passed through the tricuspid valve to the right ventricle, which pumps it to the lungs. Oxygenated blood (red) from the lungs travels through the pulmonary veins to the heart’s left atrium, then through the mitral valve to the left ventricle, which pumps the blood out to the rest of the body.

Graphic showing the basic anatomy and function of the human heart

Infographic: Alisdair Macdonald

Three kinds of defect

The anatomy of each SVD differs, but they all result in a mix of oxygenated and deoxygenated blood being pumped to the body and lungs. This means that vital organs don’t get enough oxygen.

Graphic illustrating three kinds of heart defect

Infographic: Alisdair Macdonald

A solution in stages

SVDs are treated with a sequence of three operations2. Together, these surgeries ensure that the deoxygenated blood returning from the body bypasses the heart and goes straight to the lungs. The heart is then left to pump only oxygenated blood — getting rid of the problem of mixed blood.

Graphic illustrating the three surgical procedures for SVDs

Infographic: Alisdair Macdonald

Comorbidities are common

Complications: Children born with SVDs can live into their 30s and 40s, but they have a significantly higher chance of experiencing other diseases as compared with healthier adults37.

Bar chart showing relative risk that adults with SVDs will experience other diseases

Infographic: Alisdair Macdonald

In utero surgery

Surgeons have begun to pioneer procedures to start treatment from within the womb.

Graphic illustrating featl balloon atrial septostomy

Infographic: Alisdair Macdonald

Nature 599, S22-S23 (2021)


This article is part of Nature Outline: Single-ventricle heart defects, an editorially independent supplement produced with the financial support of third parties. About this content.


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