Pulmonary valve stenosis is a narrowing of the valve between the lower right heart chamber and the lung arteries. In a narrowed heart valve, the valve flaps may become thick or stiff. This reduces blood flow through the valve.

Pulmonary stenosis

Pulmonary stenosis

In pulmonary stenosis, the pulmonary valve is narrowed. The greater the narrowing, the harder the lower right heart chamber, called the right ventricle, must work to pump blood to the lungs. The increased pressure causes the right ventricle to become thick.

Usually, pulmonary valve disease is caused by a heart problem that develops before birth. A heart problem present at birth is called a congenital heart defect. In adults, pulmonary valve stenosis may be a complication of another illness.

Pulmonary valve stenosis ranges from mild to severe. Some people with mild pulmonary valve stenosis don't have symptoms. They may need only occasional health checkups. Moderate and severe pulmonary valve stenosis may need a procedure to repair or replace the valve.


Pulmonary valve stenosis symptoms depend on how much blood flow is blocked. Some people with mild pulmonary stenosis do not have symptoms. Those with more-severe pulmonary stenosis may first notice symptoms while exercising.

Pulmonary valve stenosis symptoms may include:

  • A whooshing sound called a heart murmur that can be heard with a stethoscope.
  • Fatigue.
  • Shortness of breath, especially during activity.
  • Chest pain.
  • Fainting.

Babies with pulmonary valve stenosis may have blue or gray skin due to low oxygen levels.

When to see a doctor

Talk to your health care provider if you or your child has:

  • Shortness of breath.
  • Chest pain.
  • Fainting.

Prompt diagnosis and treatment of pulmonary valve stenosis can help reduce the risk of complications.


Pulmonary valve stenosis usually results from a heart problem present at birth. The exact cause is unclear. The pulmonary valve doesn't develop properly as the baby is growing in the womb.

The pulmonary valve is made of three thin pieces of tissue called flaps, also called cusps. The cusps open and close with each heartbeat. They make sure blood moves in the right direction.

In pulmonary valve stenosis, one or more of the cusps may be stiff or thick. Sometimes the cusps may be joined together. That means they are fused. So the valve doesn't open fully. The smaller opening makes it harder for blood to leave the lower right heart chamber. Pressure increases inside the chamber. The increased pressure strains the heart. Eventually the lower right heart chamber wall gets thicker.

Risk factors

Things that may increase the risk of pulmonary valve stenosis include:

  • German measles, also called rubella. Having German measles during pregnancy increases the risk of pulmonary valve stenosis in the baby.
  • Noonan syndrome. This condition is caused by altered DNA. It can lead to many problems with the heart's structure and function.
  • Rheumatic fever. This complication of strep throat can cause permanent damage to the heart and heart valves. It increases the risk of developing pulmonary valve stenosis later in life.
  • Carcinoid syndrome. This condition occurs when a rare cancerous tumor releases certain chemicals into the bloodstream. It causes shortness of breath, flushing and other symptoms. Some people with this syndrome develop carcinoid heart disease, which damages heart valves.


Possible complications of pulmonary stenosis include:

  • Infection of the lining of the heart, called infective endocarditis. People with heart valve problems, such as pulmonary stenosis, have an increased risk of developing bacterial infections that affect the inner lining of the heart.
  • Irregular heartbeats, called arrhythmias. People with pulmonary stenosis are more likely to have irregular heartbeats. Unless the stenosis is severe, irregular heartbeats due to pulmonary stenosis usually aren't life-threatening.
  • Thickening of the heart muscle. In severe pulmonary stenosis, the lower right heart chamber must pump harder to force blood into the pulmonary artery. The strain on the heart causes the muscular wall of the ventricle to thicken. The condition is called right ventricular hypertrophy.
  • Heart failure. If the right ventricle can't pump properly, heart failure eventually develops. Symptoms of heart failure include fatigue, shortness of breath, and swelling of the legs and belly area.
  • Pregnancy complications. The risks of complications during labor and delivery are higher for those with severe pulmonary valve stenosis than for those without it.

Dec 20, 2022

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