Pulmonary Atresia

What is pulmonary atresia?

Pulmonary atresia is type of heart defect that a baby is born with. It occurs when the pulmonary valve — normally located between the right ventricle and the pulmonary artery — doesn’t form properly. This means that blood can’t flow from the heart to the lungs to get oxygen to the body. In some cases, babies with pulmonary atresia may also have a small, or missing, right ventricle that can’t properly pump blood to the lungs.

Pulmonary atresia is a life-threatening condition, affecting one out of every 10,000 newborns. Babies born with pulmonary atresia need medication and surgery to correct the heart defect and improve blood flow to the lungs.

How does pulmonary atresia look compared to a normal heart?

In a normal heart, blood enters the heart through the right atrium. From there, it flows through the right ventricle to the pulmonary artery and then into the lungs, where it receives oxygen. This oxygen-rich blood then returns to the heart via the left atrium, passes into the left ventricle, and is pumped through the aorta out, supplying the rest of the body with oxygen.

When a baby has pulmonary atresia, the pulmonary valve is not formed normally, so the blood cannot pass from the right ventricle into the lungs as it should.

Image of a normal heart and a heart with pulmonary atresia

What are the two forms of pulmonary atresia?

There are two main types of pulmonary atresia. The major difference is whether the baby also has a ventricular septal defect (VSD), which is a hole between the right and left ventricles.

  • Pulmonary atresia with intact ventricular septum (PA/IVS): With this type of pulmonary atresia, there’s no VSD, so the right ventricle receives little blood flow before birth and can become small and underdeveloped. If the right ventricle is very small, it can’t perform its role as a pumping chamber. The coronary arteries, a type of blood vessel that provides fresh blood to the heart muscle, may not develop correctly. In these cases, the blood supply to the heart may be provided directly from the right ventricle through abnormal connections called coronary fistulas. It is important for your doctor to determine if the heart is dependent upon blood supply arising directly from the right ventricle.
  • Pulmonary atresia with ventricular septal defect (PA with VSD): In this type of pulmonary atresia, the hole in the ventricular septum (VSD) allows blood to flow in and out of the right ventricle. This blood flow may help the right ventricle maintain size. PA with VSD is often related to another condition called tetralogy of Fallot. In those cases, it is referred to as tetralogy of Fallot with pulmonary atresia.

Care for pulmonary atresia

The Benderson Family Heart Center at Boston Children’s Hospital treats some of the most complex pediatric heart conditions in the world. We provide families with a wealth of information, resources, programs and support — before, during and after your child’s treatment. With our compassionate, family-centered approach to expert treatment and care, your child is in the best possible hands.

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