Pulmonary Stenosis

What is pulmonary stenosis?

When the heart squeezes, the right ventricle (the lower right chamber) pumps blood out into the pulmonary artery, which then takes blood to the lungs. The pulmonary valve (also known as the pulmonic valve) is located between the right ventricle and the main pulmonary artery. The pulmonary valve's job is to prevent blood from leaking back into the heart between beats.

A normal pulmonary valve is made up of three thin sections. In pulmonary stenosis, two of the sections are stuck together or are too thick. There also may be fewer than three sections and as a result, the pulmonary valve is too narrow. To compensate, the heart has to work harder to pump enough blood through the valve, and to the body. Pulmonary stenosis can be mild, moderate, severe or life-threatening.

This condition is also called pulmonic stenosis or pulmonary valve stenosis. When the blockage is below the pulmonary valve, because of too much muscle (muscular bundles), it’s called subpulmonic stenosis. When the stenosis is above the pulmonary valve – In the pulmonary artery itself –it’s called supravalvular pulmonic stenosis.

Signs and symptoms of pulmonary stenosis

Pulmonary stenosis usually does not cause symptoms in infants or small children. However, as the child grows older, abnormal signs and symptoms may appear, including:

  • Fatigue
  • A heart murmur (an extra heart sound when a doctor listens to the child’s heart with a stethoscope)
  • Chest pain or fainting

Testing and diagnosis of pulmonary stenosis

In rare cases, newborns have life-threatening pulmonary stenosis, which requires immediate medical attention. Severe cases of pulmonary stenosis are sometimes diagnosed before birth, through the Fetal Heart Program at Children's Hospital of Philadelphia. 

The Cardiac Center at CHOP typically diagnoses pulmonary stenosis after a primary care doctor detects a heart murmur and refers a child to us. To confirm a suspected diagnosis of pulmonary stenosis, some of all of these tests may be used:

  • Pulse oximetry: a painless way to monitor the amount of oxygen in the blood
  • Chest X-ray
  • Echocardiogram (also called an "echo" or ultrasound): sound waves are used to see the internal structure of the heart
  • Electrocardiogram (ECG): measures the electrical activity in the heart
  • Cardiac MRI: a three-dimensional picture of the heart arteries and veins
  • Cardiac catheterization: a thin tube is inserted into the heart through a vein and/or artery in either the leg or, in very young children, through the belly button

Pulmonary stenosis can run in families, so be sure to tell your cardiologist if there is a history of a heart murmur in other close family members.

Treatment for pulmonary stenosis

Treatment for pulmonary stenosis will depends on a child’s  heart anatomy and function. For children with mild pulmonary stenosis, treatment is not usually required. However, if the child has moderate, severe or life-threatening pulmonary stenosis, treatment is needed. 

Cardiac catheterization

Cardiac catheterization, may be used as a treatment in addition to a testing. During cardiac catheterization, an interventional cardiologist will insert a thin tube (catheter) into a vein in the child’s leg, then guide it to the child’s heart. The catheter will have a balloon on the end of it. The balloon will be briefly inflated to open up the narrow valve, then deflated and withdrawn. Sometimes, two catheters and balloons are used.

After a cardiac catheterization, older children will typically spend one night in the hospital, in CHOP’s dedicated post-catheterization recovery unit, before returning home. The child will need to rest for a few days after the procedure, but then can resume normal activity. Newborns with critical conditions or children who are already inpatients at CHOP may stay in the hospital slightly longer, either in the Evelyn and Daniel M. Tabas Cardiac Intensive Care Unit (CICU), where they will receive around-the-clock attention from a team of dedicated cardiac critical care medicine specialists, or the Cardiac Care Unit (CCU).


In rare cases, surgery is required to treat pulmonary stenosis. Surgeons will cut open or cut out the valve.

Surgery for for subpulmonic and supravalvular stenosis

Subpulmonic and supravalvular pulmonic stenosis do not get better with cardiac catheterization and will require surgery if blockage is moderate or severe. Surgery for subpulmonic stenosis involves cutting out the extra muscles below the valve. Surgery for supravalvular pulmonic stenosis involves enlarging the pulmonary artery with a patch.

Both surgeries are performed at CHOP with positive outcomes. 

Outlook for pulmonary stenosis

Today, most children with heart conditions such as pulmonary stenosis go on to lead healthy, productive lives as adults. Research is also being done on innovative ways of treating pulmonary stenosis, including tissue-engineered valve replacements. A patient's new valve would be grown with their own cells on a biodegradable mesh. Still in the research and development phase, this is an exciting treatment option for pulmonary stenosis that may be available in the near future.

Follow-up care for pulmonary stenosis

Through 18

Children with pulmonary stenosis require regular checkups with a pediatric cardiologist throughout their lives. Some children must also stay on medicine and may need to limit their physical activity.

As your child grows, blood may begin to leak through the abnormal valve. This is called pulmonary regurgitation or pulmonic insufficiency. The blockage can also come back in some children. If this happens, cardiac catheterization can be repeated, as long as there isn't too much regurgitation. In severe cases, additional surgery may be necessary.

At Children’s Hospital of Philadelphia, our pediatric cardiologists follow patients until they are young adults and coordinate care with primary care physicians.

Into adulthood

Adults who were born with pulmonary stenosis must continue to see a cardiologist. CHOP’s Cardiac Center can help with the transition to an adult cardiologist. All patients with pulmonary valve disease will need lifelong follow-up with a cardiologist.

The Philadelphia Adult Congenital Heart Center, a joint program of CHOP and the University of Pennsylvania, meets the unique needs of adults who were born with heart defects.

Reviewed by Paul Stephens, MD

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