Pulmonary atresia (uh-TREE-zhuh) is one of several heart valve defects that is found at birth or shortly afterward. In pulmonary atresia, the valve that allows blood to flow from the heart to the lungs (pulmonary valve) doesn't work correctly. Instead of opening and closing to allow blood to travel from the heart to the lungs, a sheet of tissue or muscle blocks blood flow.

Usually, some blood travels to the lungs through other passages within the heart and its arteries. Before birth, blood entering the right side of your baby's heart passes through a hole between the top chambers (foramen ovale), so the oxygen-rich blood can be pumped out to the rest of your baby's body.

After birth, the foramen ovale normally closes, but may stay open in pulmonary atresia. Another temporary opening (ductus arteriosus) may allow some blood flow to the lungs after birth, but your baby will need medication, procedures or surgery to correct the defect.

Several tests may be used to diagnose pulmonary atresia, including:

• Echocardiogram. In an echocardiogram, sound wave movement shows the features of your child's heart. Your doctor might also use an echocardiogram of your abdomen before you deliver your baby (fetal echocardiogram) to diagnose pulmonary atresia.
• Electrocardiogram (ECG). In this test, sensor patches with wires attached (electrodes) measure the electrical impulses given off by your baby's heart. An ECG reveals abnormal heart rhythms (arrhythmias or dysrhythmias) and may show other heart problems.
• Cardiac catheterization. In catheterization, your baby's doctor inserts a thin, flexible tube (catheter) into a blood vessel in your baby's groin and guides it to your baby's heart. This test shows your baby's heart structure and the blood pressure and oxygen levels in your baby's heart, pulmonary artery and aorta. The doctor may inject a dye into the catheter to make your baby's arteries visible under X-ray.
• Pulse oximetry. This test indicates how much oxygen your baby is getting through his or her blood.
• X-ray. An X-ray shows your baby's doctor the size of your baby's pulmonary atresia, as well as bones and other tissues.

Your baby's doctor may suggest several different approaches to caring for your baby, including:

Medication

Your baby's doctor may give your baby a medication called prostaglandin intravenously to prevent the ductus arteriosus from closing before the doctor performs a procedure.

Procedures

Your baby most likely will require one or more procedures to improve heart function and blood flow. Some procedures are done in the first days to weeks of your baby's life, and others are done later.

Procedures in the first days to weeks of life

• Balloon valvotomy. If the leaflets in your baby's pulmonary valve are fused, your doctor might create a small hole at the center of the valve using a small amount of energy (radiofrequency ablation) or a wire and then open the leaflets using a balloon.
• Ductal stent placement. Placement of a rigid tube (stent) in the channel that connects the aorta and pulmonary artery (ductus arteriosus) permits blood to travel to the lungs.
• Balloon atrial septostomy. In rare circumstances, your doctor also may use a balloon to open up the foramen ovale, which may close soon after birth or becomes restrictive. This increases the amount of blood that can be pumped to the lungs.
• Systemic-to-pulmonary artery shunt. This is a surgical procedure that may be needed in the first few days of life to increase blood flow to the lungs by creation of a connection (shunt) between one of the arteries and the pulmonary artery using a small tube of synthetic material. One example of such procedure is the Blalock-Taussig shunt (BT shunt). This represents the first-stage palliation until your baby is big enough to undergo the second stage.

Later surgical procedures

• Bidirectional Glenn procedure. In this procedure, your baby's surgeon attaches the blood vessel that receives blood from the upper body (superior vena cava) to the pulmonary artery. This procedure is usually done between 4 and 6 months of age. This sometimes can be performed without the need to use the heart-lung machine (off-pump Glenn).
• Fontan procedure. During this procedure, which is typically done when your child is 2 or 3 years old, the surgeon will connect the blood vessel that handles blood from the lower body (inferior vena cava) to the pulmonary artery. This serves to restore the oxygen level back to normal and represents the final stage. This also can be performed without the use of the heart-lung machine (off-pump Fontan).
• One and one-half ventricle repair. In this procedure, the surgeon connects the superior vena cava to the pulmonary artery (bidirectional Glenn). This can be the final procedure if the right ventricle in your baby's heart is big enough and will not require the Fontan procedure. This approach reduces the likelihood of the long-term issues that can occur with the Fontan procedure.
• Hybrid procedures. Hybrid procedures involve a surgeon and a cardiologist who specializes in catheter procedures. In a hybrid procedure, surgical and catheter procedures are performed at the same operation, sometimes without the use of the heart-lung machine.