A congenital heart defect, pulmonary stenosis affects the pulmonary valve between the right ventricle of the heart and the pulmonary artery that carries oxygen-depleted blood from the heart to the lungs. If the valve doesn’t open properly, pulmonary stenosis may be diagnosed. Pulmonary stenosis can also happen if the area on either side of the valve in the ventricle or artery is too narrow to allow enough blood to reach the lungs. Moderate to severe pulmonary stenosis can worsen over time but treatments can be very effective and your child should be able to have a healthy, active life.

Wellness & Prevention

Pulmonary stenosis occurs in the first eight weeks of fetal development as the heart’s four chambers develop from a hollow tube. The pulmonary valve has three leaflets that let blood flow into the pulmonary artery and prevent blood from flowing backward into the right ventricle. With pulmonary stenosis, the valve may not open fully because the leaflets are too thick or partially fused together. Pulmonary stenosis can also occur if the heart muscle under the valve is too thick, constricting the flow of blood through the valve, or the pulmonary artery is too narrow.

A defective valve or slim passageway forces the right ventricle to work harder to push blood through the smaller opening. With time, the right ventricle can tire and stop pumping efficiently, causing higher blood pressure in the right atrium (upper chamber) and veins returning blood to the heart. Your child may suffer congestive heart failure as a result. With PS, the right ventricle can thicken from being overworked, increasing the risk of a cardiac arrhythmia. Children with defective heart valves are also at a higher risk for developing infective endocarditis, an infection of the heart’s inner lining or a heart valve.

The severity of pulmonary stenosis varies. Children with mild PS may not have any symptoms. Children who have severe PS may experience significant symptoms and may feel very sick. Symptoms can include:

  • Rapid heart rate
  • Fatigue
  • Shortness of breath
  • Swell in the feet, ankles, face, eyelids or abdomen
  • Heavy or rapid breathing
  • Heart murmur
  • Trouble feeding
  • Poor weight gain
  • A blue color in the skin, lips and nails


During a physical examination, your child’s doctor may hear a heart murmur, the extra noise caused by obstructed blood flow. She may recommend that your child see a pediatric cardiologist for a diagnosis. Cardiologists confirm a diagnosis of pulmonary stenosis using different methods.

  • Chest X-ray: An X-ray creates an image that shows your pediatric cardiologist the size and shape of your child’s heart and lungs.
  • Electrocardiogram (ECG or EKG): An electrocardiogram maps electrical activity in the heart. An ECG detects stress on the heart muscle and shows abnormal heartbeats, such as an arrhythmia.
  • Echocardiogram: Using ultrasound technology, an echocardiogram produces an image of the heart and its valves and assesses the heart’s structure and function. An echocardiogram also shows how blood flows through the heart.
  • Cardiac catheterization: Inserted through a larger blood vessel, a tiny catheter is threaded into the heart to take blood pressure and oxygen measurements in the aorta, pulmonary artery and all four chambers.

Pulmonary stenosis may also be diagnosed from MRI or CT scan images or a low-pulse oximetry test to measure oxygen levels.


If your child has mild to moderate pulmonary stenosis, treatment may not be necessary. Your pediatric cardiologist will likely recommend regular appointments to monitor your child’s heart function and ensure PS doesn’t worsen.

Child with severe to critical pulmonary stenosis require treatment to repair the valve. Treatment options include:

  • Balloon valvuloplasty: Using cardiac catheterization, a pediatric cardiologist inflates a balloon in the pulmonary valve to widen the opening and improve blood flow.
  • Surgery: A pediatric cardiac surgeon can perform several different procedures to treat pulmonary stenosis. Scar tissue may be released in the leaflets. The valve may be removed and replaced with an outflow patch. A patch may be used to enlarge a narrowed area. The valve may be replaced.


After recuperating from treatment, most children born with pulmonary stenosis can go on to lead active, unrestricted lives. Your pediatric cardiologist may recommend ongoing care for the rest of your child’s life to check on her heart and the pulmonary valve. Another balloon valvuloplasty may be needed to stretch the valve again or the valve may need to be replaced as your child grows.