Pulmonary stenosis

What is pulmonary stenosis?

Pulmonary stenosis is a congenital (present at birth) heart defect. With typical pulmonary stenosis, the pulmonary valve doesn’t develop as it should in a baby in the womb. In a typical heart, the pulmonary valve has three flaps (leaflets) that open and close with each heartbeat. The valve helps send blood from the heart through the pulmonary artery to the lungs to pick up oxygen.

With pulmonary stenosis, the abnormal valve might be stiff, too narrow or too small, preventing it from opening and closing properly. This condition forces a baby’s heart to pump harder to send enough blood to the lungs, straining the heart over time.

Blood flow in a healthy heart

What are the different types of pulmonary stenosis?

Pulmonary stenosis is a congenital heart disease, which means that a baby is born with a condition that affects the structure of their heart. This condition occurs in the right side of the heart, which affects blood flow to the lungs.

The types of pulmonary stenosis include an abnormal pulmonary valve and other problems that partially restrict blood flow from the heart to the lungs. Each type has a different level of stenosis (narrowing).

• Pulmonary valve stenosis - The pulmonary valve has thickened and/or narrowed leaflets that don’t open and close the way they should.

• Supravalvular pulmonary stenosis - A child’s heart has a narrowed area in the pulmonary artery, just above the pulmonary valve.

• Subvalvular pulmonary stenosis - Thickened heart muscle that has developed below the pulmonary valve can cause narrowing in that area.

• Peripheral (branch) pulmonary stenosis - As the pulmonary artery leaves the heart, it branches into two vessels, one carrying blood to each lung. With peripheral (branch) pulmonary stenosis, one or both branches are narrowed.

What are the signs and symptoms of pulmonary stenosis?

Infants

• Cyanosis (bluish color in skin) due to low oxygen in the blood

• Trouble feeding

Children at any age

• Heart murmur or fast heart rate

• Rapid breathing or shortness of breath

• Pale, cool or clammy skin

• Lack of energy or exhaustion, especially with physical activity

• Signs of heart failure, such as swelling in the face, abdomen (belly), ankles or feet

The signs and symptoms of pulmonary valve stenosis vary depending on how much the blood flow is blocked. With severe blockage, the signs are noticeable shortly after birth. With less blockage, children may experience no or mild signs or symptoms, or symptoms might not appear until later in life.

How is pulmonary stenosis diagnosed?

Doctors sometimes detect signs of pulmonary valve stenosis, using fetal imaging, in a baby before birth if the blockage is severe. In most cases, we diagnose the condition after birth in newborns or in older children when their primary care provider hears a heart murmur and refers them to us.

At Children's Health, our heart specialists begin with a thorough evaluation and physical exam, listening carefully to your child’s heart and checking their blood oxygen levels. We ask you about your child’s personal and family medical history, including whether any family members have had a heart murmur.

To confirm a diagnosis and plan treatment for pulmonary stenosis, we may recommend one or more tests, such as:

• Chest X-rays are used to look for changes in the heart or pulmonary artery

• Electrocardiogram (EKG or ECG) is used to evaluate the heart’s electrical activity for signs of thickened heart muscle

• Echocardiogram (heart ultrasound) is used to examine the heart’s structure

• Doppler echocardiogram is used to assess blood flow through the heart to estimate the severity of the blockage

• Other cardiac imaging such as cardiac MRI or CT scans, is used to evaluate the structure of the heart and pulmonary artery

• Cardiac catheterization is a minimally invasive procedure that uses catheters (thin, flexible tubes) inserted through blood vessels to access and examine the heart

What causes pulmonary stenosis?

Pulmonary stenosis occurs when parts of a baby's heart don't form properly in the womb. This congenital heart disease usually occurs by chance, and the reasons are unknown. Nothing that a mother did or didn't do during her pregnancy causes pulmonary stenosis.

How is pulmonary stenosis treated?

Our pediatric cardiologists work with you to decide on your child’s treatment options based on the severity of the stenosis and their symptoms, their overall health and other factors.

• If the condition is mild, your child might not need treatment right away or might need only medications to manage symptoms. Our cardiologists partner with your child’s doctor to monitor their health for changes that may require treatment.

• For more severe stenosis and symptoms, a child may need a procedure to treat the pulmonary valve.

Most often, we can treat pulmonary valve stenosis with catheterization techniques, including:

• Balloon dilation or valvuloplasty - Our pediatric interventional cardiologists (heart specialists who perform cardiac catheterization) use a catheter with a balloon at its tip. At the narrowed area, the doctor inflates the balloon to widen the area. Children can usually go home the same day or the day after a catheterization procedure.

• Catheter valve replacement - Our cardiologists perform a catheter procedure to replace the defective valve with an animal tissue valve.

• Surgery - In a few cases, children may need heart surgery to repair pulmonary stenosis.

Our skilled pediatric heart surgeons have expertise in:

• Valvotomy - Surgeons operate to release narrowed or thickened valve leaflets, allowing them to open and close properly.

• Surgical valve replacement - Surgeons perform surgery to replace the valve that’s not working properly.

• Subvalve muscle resection and/or patch enlargement - When needed, we perform this technique to remove muscle under the valve or enlarge a narrowed area with a patch. We can perform these procedures during valve replacement surgery or in a separate procedure.