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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.

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.

Our Approach to Pulmonary Stenosis

UCSF provides comprehensive, highly specialized care for adults living with heart defects such as pulmonary stenosis. Our dedicated team of experts offers a wide array of services, including thorough medical evaluations, advanced treatments, long-term monitoring, and personalized recommendations on diet, exercise, psychosocial support and family planning.

Surgeons may be able to repair the defect using a minimally invasive procedure called balloon valvuloplasty. During this procedure, the physician uses a thin, flexible tube to place and inflate a balloon in the narrowed valve, stretching it open, then deflates and withdraws the balloon. Balloon valvuloplasty is usually successful. However, adults with severe pulmonary stenosis often need to have the valve replaced entirely, with either a manufactured valve or an animal valve.

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Signs & symptoms

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.

In adults with severe stenosis, the valve is often stiff and calcified, and treatment is more likely to include surgical replacement with either a manufactured valve or a valve from an animal, usually a pig. Another surgical repair involved removing obstructive tissue below the valve, which may be done in conjunction with valve replacement. Studies indicate that surgical valvotomy has a 25-year survival rate of 95 percent, or about the same as the normal population.

Most patients who have been treated surgically or with balloon valvuloplasty in childhood will have normal lives. They usually do not require continuous antibiotic treatment but it may be recommended for some people who have additional complications. The likelihood of requiring a repeat procedure is very low — 5 percent at 25 years. However, it is recommended that all patients be evaluated by a cardiologist specializing in adult congenital heart disease at least once. At that time, an echocardiogram should be performed. Thereafter, yearly physical examinations are recommended with repeat echocardiogram should there be a change in the physical examination or new symptoms.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.

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