The outlook for people with pulmonary atresia, a congenital heart defect that blocks blood flow to the lungs, has significantly improved with recent medical advancements.

Pulmonary atresia presents a unique challenge in pediatric cardiology in which the intricate pathways of the heart can be disrupted from the very start. The infant’s heart finds it difficult to send oxygen-rich blood to the lungs, which is crucial for sustaining life.

Let’s explore pulmonary atresia, its symptoms, risk factors, and the notable increase in survival rates observed in the last few decades.

Pulmonary atresia is a serious congenital heart irregularity that develops during fetal development. In this condition, the pulmonary valve, which controls blood flow from the heart to the lungs, doesn’t form properly. This prevents blood from flowing to the lungs to pick up oxygen, leading to severe health issues such as heart failure.

There are two main types of pulmonary atresia, depending on whether there’s a hole in the wall between the heart’s lower chambers (ventricular septum).

  • Pulmonary atresia with an intact ventricular septum: The wall between the ventricles is intact, so the right ventricle and pulmonary artery are very small. This can lead to difficulties pumping blood to the lungs and body.
  • Pulmonary atresia with ventricular septal defect (PA-VSD): There’s a hole in the wall between the ventricles, allowing some blood to flow into the right ventricle. This can help the right ventricle develop better, but it still has difficulty pumping blood to the lungs.

Symptoms of pulmonary atresia can vary depending on the severity of the condition and the presence of other heart irregularities.

Common symptoms may include:

  • bluish discoloration of the skin, lips, and nail beds (cyanosis)
  • rapid breathing or shortness of breath
  • fatigue or weakness, especially during feeding or exertion
  • poor growth or development
  • irritability or fussiness
  • heart murmur (an abnormal sound heard during a heartbeat)

In severe cases, newborns may develop severe cyanosis and respiratory distress shortly after birth. Symptoms can worsen over time if left untreated, leading to heart failure and other complications.

Pulmonary atresia is typically diagnosed in the womb (evident at 18–22 weeks gestation) or shortly after birth. The diagnosis is often made based on prenatal ultrasound findings that show abnormalities in the baby’s heart. After birth, a physical examination may reveal symptoms such as a heart murmur or bluish discoloration of the skin.

Further diagnostic tests may include:

  • Echocardiogram: An echocardiogram uses ultrasound to visualize the heart’s structure and function, confirming the diagnosis and assessing severity.
  • Electrocardiogram (EKG): An EKG records the heart’s electrical activity, identifying abnormalities in rhythm or structure.
  • Chest X-ray: A chest X-ray shows heart and lung blood vessel size and shape.
  • Cardiac catheterization: A cardiac catheterization involves inserting a catheter into a blood vessel and guiding it to the heart for detailed information.
  • MRI or CT scan: An MRI scan or CT scan provides detailed heart and blood vessel images.

The exact cause of pulmonary atresia is unknown, but it’s believed to result from a combination of genetic and environmental factors.

Pulmonary atresia occurs during fetal development when the baby’s heart is forming. It happens when the valve that controls blood flow from the heart to the lungs doesn’t form correctly, leading to a blockage that prevents blood from reaching the lungs.

Pulmonary atresia risk factors

Risk factors for pulmonary atresia include:

  • Genetic factors: A family history of congenital heart irregularities can increase the risk of a child being born with pulmonary atresia. Research has discovered new genes linked to pulmonary atresia through whole exome sequencing.
  • Maternal factors: Certain maternal factors during pregnancy, such as maternal diabetes, smoking, older age during pregnancy, or intake of teratogenic drugs (medications that affect the fetus), may increase the risk of congenital heart irregularities in the baby, including pulmonary atresia.

In general, the goal of treatment is to improve blood flow to the lungs and alleviate symptoms.

A common approach is surgery to create a pathway for blood to reach the lungs. This can involve creating a connection between the right ventricle and the pulmonary arteries (a shunt) or enlarging the pulmonary valve. In some cases, a series of surgeries may be necessary over time to further improve blood flow.

Management of pulmonary atresia typically requires lifelong care, especially in complex cases or with associated heart irregularities.

Pulmonary atresia surgery success rates

The success rates of surgery for pulmonary atresia depend on various factors, including the specific type of pulmonary atresia, the presence of other heart irregularities, and the overall health of the infant.

A study of 107 infants with PA-VSD who underwent surgery between 1989 and 2019 found that most (85%) had a complete repair at around 1 year old. Survival rates were 90% at 6 months, 85% at 20 months, and 81% at 10 years after surgery.

Using smaller shunts during surgery led to quicker complete repairs but also increased the risk of complications between surgeries. Overall, staged repair for PA-VSD showed high success rates for complete repair and long-term survival.

What is the survival rate for pulmonary atresia?

Pulmonary atresia can be a serious condition with a risk of death, especially without appropriate treatment. But with advances in medical and surgical care, the outlook for individuals with pulmonary atresia has improved significantly, and many can lead relatively normal lives with appropriate management.

In a study of 88 children who received a diagnosis of PA-VSD, survival rates were strong over the past decade: 95% at 1 year, 83.7% at 5 years, and 79.6% at 10 years.

Another study of 171 children with pulmonary atresia and intact ventricular septum, a rarer form, showed improved 1-year survival from 76% to 92% between 1980–1998 and 1999–2016, respectively.

Membranous pulmonary atresia survival increased from 78% to 98%, and muscular pulmonary atresia survival increased from 68% to 85%. Risk factors for death included other health issues and specific pulmonary artery types.

Pulmonary atresia is a congenital heart irregularity in which the pulmonary valve doesn’t form properly, blocking blood flow from the heart to the lungs. Treatment often involves surgery to create a pathway for blood flow.

With modern medical and surgical advancements, most infants born with pulmonary atresia now survive into adulthood. The exact survival rate varies, but overall, there has been a significant improvement in survival rates in recent years.