Pulmonary Stenosis

Pulmonary stenosis is a narrowing of the pulmonary valve that regulates the flow of blood from the right ventricle to the lungs. This narrowing may force the heart to pump harder to send blood to the lungs and lead to enlargement of the heart.

The heart consists of four chambers. The two upper chambers, called atria, where blood enters the heart and the two lower chambers, called ventricles, where blood is pumped out of the heart. The flow between the chambers is controlled by a set of valves that act as one-way doors.

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Blood is pumped from the right side of the heart up through the pulmonary valve to the pulmonary artery to the lungs, where the blood is filled with oxygen. From the lungs, the blood travels back down to the left atrium and left ventricle. The newly oxygenated blood is pumped through another big blood vessel called the aorta to the rest of the body.

The pulmonary valve has three leaflets or valves that work to open and close the valve. Stenosis occurs when the valve does not open fully and obstructs blood flow. Stenosis may occur because the valve is deformed with only one or two leaflets, or because the leaflets are stuck together.

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People with pulmonary stenosis often have no symptoms. However, if the condition is severe, symptoms may include:

  • Turning blue, called cyanosis
  • Rapid breathing
  • Fainting
  • Low energy

Because there may be no obvious symptoms, the first indication of pulmonary stenosis is often a heart murmur, an extra sound heard during a chest examination. Pulmonary stenosis evaluation includes:

  • Electrocardiogram (EKG or ECG), which records the heart's electrical activity
  • Chest X-ray to see the heart's size
  • Echocardiogram, which is an ultrasound examination of the heart
  • Exercise test to measure how much oxygen the heart can provide to your muscles while you exercise

Severity determines treatment. Patients with very mild obstruction and no symptoms may not require treatment. For others, pulmonary stenosis may need to be be treated with a procedure called a valvuloplasty. This procedure is minimally invasive, which means it requires only a small incision. A more severe problem may require an open-heart operation, which is major surgery.

Children and adults whose pulmonary valves are still flexible may be treated with a balloon valvuloplasty, a non-surgical procedure in which a catheter — a thin, flexible, plastic tube — is inserted into the heart via blood vessels from the leg. A balloon at the tip of the catheter is inserted into the narrow opening in the valve and then inflated to stretch the valve opening and separate the valve leaflets. This is usually very successful and permanent. If, however, the valve is unusually thick, then the balloon procedure is unlikely to be successful and the surgeon will have to open up the valve with a scalpel.

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Reviewed by health care specialists at UCSF Medical Center.

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