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

Usually, pulmonary valve disease results from a heart problem that develops before birth (congenital heart defect). However, adults may develop pulmonary valve stenosis as a complication of another illness.

Pulmonary valve stenosis ranges from mild to severe. Some people with mild pulmonary valve stenosis don't notice any symptoms and may only require occasional doctor's checkups. Moderate and severe pulmonary valve stenosis may require a procedure to repair or replace the valve.


Pulmonary valve stenosis signs and symptoms vary, depending on how much blood flow is blocked. Some people with mild pulmonary stenosis don't have symptoms. Those with more-severe pulmonary stenosis may first notice symptoms while exercising.

Pulmonary valve stenosis signs and symptoms may include:

  • A whooshing sound (murmur) that can be heard with a stethoscope
  • Fatigue
  • Shortness of breath, especially during activity
  • Chest pain
  • Loss of consciousness (fainting)

Babies with pulmonary valve stenosis and other congenital heart defects may appear blue (cyanotic).

When to see a doctor

Talk to your doctor if you or your child has:

  • Shortness of breath
  • Chest pain
  • Fainting

If you or your child has pulmonary stenosis or another heart problem, prompt diagnosis and treatment can help reduce the risk of complications.


Pulmonary valve stenosis is most often a congenital heart defect. 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 (cusps). The cusps open and close with each heartbeat and make sure blood moves in the right direction.

In pulmonary valve stenosis, one or more of the cusps may be stiff or thick, or the cusps may be joined (fused) together. As a result, the valve doesn't open fully. The smaller valve opening makes it harder for blood to flow out of the lower right heart chamber (right ventricle). Pressure increases inside the right ventricle as it tries to push blood through the smaller opening. The increased pressure creates a strain on the heart that eventually causes the right ventricle's muscular wall to thicken.

Risk factors

Conditions or disorders that may increase the risk of pulmonary valve stenosis include:

  • German measles (rubella). Having German measles (rubella) during pregnancy increases the risk of pulmonary valve stenosis in the baby.
  • Noonan syndrome. This genetic disorder causes various problems with the heart's structure and function.
  • Rheumatic fever. This complication of strep throat can cause permanent damage to the heart, including the heart valves. It can increase the risk of developing pulmonary valve stenosis later in life.
  • Carcinoid syndrome. A rare cancerous tumor releases certain chemicals into the bloodstream, causing shortness of breath, flushing and other signs and 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 (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 heartbeat (arrhythmia). People with pulmonary stenosis are more likely to have an irregular heartbeat. 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 heart's right ventricle must pump harder to force blood into the pulmonary artery. The strain on the heart causes the muscular wall of the ventricle to thicken (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 abdomen.
  • Pregnancy complications. The risks of complications during labor and delivery are higher for those with severe pulmonary valve stenosis than those without the condition.

Aug. 26, 2021
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