A common sign of pulmonary stenosis is a sound called a heart murmur — an abnormal whooshing sound caused by turbulent blood flow — that your doctor may hear when he or she listens to your heartbeat. Other signs and symptoms may include:

• Shortness of breath, especially during exertion
• Chest pain
• Loss of consciousness (fainting)
• Fatigue
• Poor weight gain (in babies)

Signs and symptoms vary, depending on the extent to which the valve is obstructed. People with mild pulmonary stenosis might have symptoms only while exercising or have none at all.

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Pulmonary valve stenosis usually occurs due to improper development of the pulmonary valve during fetal growth, often in association with other heart abnormalities present at birth (congenital). It's not certain what causes the valve to develop abnormally. There are three types of pulmonary stenosis:

• Valvular — involving the valve leaflets
• Subvalvular — below the valve
• Supravalvular — above the valve

Some people with pulmonary stenosis may have more than one type. The most common type of pulmonary stenosis is valvular.

What happens during normal circulation
During circulation, oxygen-poor blood is pumped from your heart, through the pulmonary valve and into the pulmonary artery. The pulmonary artery carries the blood to your lungs to pick up oxygen and drop off carbon dioxide.

The pulmonary valve is made up of three thin leaflets arranged in a circle, much like a three-piece pie. With each heartbeat, the valve opens in the direction of blood flow — into the pulmonary artery and continuing to the lungs — and then closes when the right ventricle relaxes to prevent blood from flowing backward into the right ventricle of the heart.

What happens in pulmonary valve stenosis
In pulmonary valvular stenosis, one or more of the leaflets may be defective or too thick, or the leaflets may not separate from each other properly. If this happens, the valve doesn't open correctly, restricting blood flow.

Other contributing conditions
Infrequently, other medical conditions or having an artificial valve can cause the condition in older people.

• Carcinoid syndrome. This syndrome is a combination of signs and symptoms, including flushing of the skin and diarrhea. Carcinoid syndrome results from the release of a chemical, serotonin, from growths called carcinoid tumors located in the small intestine. People with carcinoid syndrome may develop problems with their heart valves from the serotonin.
• Rheumatic fever. This is a complication of an infection caused by streptococcus bacteria, such as strep throat or scarlet fever. Rheumatic fever may injure the heart valves.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Pulmonary stenosis is hard to prevent because the majority of people who have this disorder are born with it. Certain conditions, including carcinoid syndrome and rheumatic fever, can increase your risk of pulmonary stenosis.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Talk to your doctor if you or your child experiences the following:

• Shortness of breath
• Fainting
• Chest pain

If you do have pulmonary stenosis or another heart problem, prompt evaluation and treatment can help reduce your risk of complications.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Pulmonary stenosis is usually diagnosed in childhood, but sometimes it isn't detected until later in life. Your doctor may suspect pulmonary stenosis if he or she hears a heart murmur in the upper left area of your chest during a routine checkup. Your doctor may then use a variety of tests to confirm the diagnosis:

• Electrocardiogram. An electrocardiogram records the electrical activity in your heart each time it contracts. During this procedure, patches with wires (electrodes) are placed on your chest, wrists and ankles. The electrodes measure electrical activity, which is recorded on paper. This test helps determine if the muscular wall of your right ventricle is thickened (ventricular hypertrophy).
• Echocardiography. Echocardiograms use high-pitched sound waves to produce an image of the heart. Sound waves bounce off your heart and produce moving images that can be viewed on a video screen. This test is useful for assessing the structure of the pulmonary valve, the location and severity of the narrowing (stenosis), and the function of the right ventricle of your heart.
• Cardiac catheterization. During this procedure, your doctor inserts a thin flexible tube (catheter) into an artery or vein in your groin and weaves it up to your heart or blood vessels. A dye is injected through the catheter to make your blood vessels visible on X-ray pictures. Doctors also use cardiac catheterization to measure the blood pressure in the heart chambers and blood vessels.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Cases of mild to moderate pulmonary stenosis generally don't cause complications. However, severe pulmonary stenosis may be associated with the following:

• Infectious endocarditis. This is an inflammation of the inner lining of the heart caused by a bacterial infection. People with pulmonary stenosis are twice as likely as people in the general population to have this condition.
• Right ventricular hypertrophy. In pulmonary stenosis, the right ventricle must pump harder to force blood into the pulmonary artery. Pumping of the right ventricle against increased pressure causes the muscular wall of the ventricle to thicken (hypertrophy) and the chamber within the ventricle to enlarge. Eventually, the heart becomes stiff and may become weakened.
• Congestive heart failure. If the right ventricle becomes weak and unable to pump efficiently, congestive heart failure develops. This results in swelling of the legs and abdomen, and can also cause fatigue and shortness of breath.
• Arrhythmia. People with pulmonary stenosis are more likely to have an arrhythmia, or irregular heartbeat. Arrhythmias associated with pulmonary stenosis are usually not life-threatening unless the stenosis is severe.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Some cases of pulmonary stenosis are mild and don't require treatment except for routine checkups. However, if your case is more serious, you may undergo either balloon valvuloplasty or open-heart surgery.

The decision to perform a balloon valvuloplasty or open-heart surgery depends on the extent to which the pulmonary valve is obstructed. Pulmonary stenosis is classified as mild, moderate or severe, depending on a measurement of the blood pressure difference between the right ventricle and pulmonary artery.

Balloon valvuloplasty
This technique uses cardiac catheterization to treat pulmonary valve stenosis. During this procedure, your doctor threads a small tube through a vein in your leg and up to your heart. An uninflated balloon is placed through the opening of the narrowed pulmonary valve. Your doctor then inflates the balloon, opening up the narrowed pulmonary valve and increasing the area available for blood flow.

The most common side effect of a balloon valvuloplasty is valve regurgitation, in which the pulmonary valve leaks after the balloon is in place. But the benefits associated with the procedure usually outweigh the risk of valve regurgitation. Also, as with most procedures, there is a risk of bleeding, infection or blood clots. Serious complications are rare and most people can expect to return to normal activity afterward.

Open-heart surgery
Balloon valvuloplasty can't be used for cases of pulmonary stenosis that occur above the pulmonary valve (supravalvular) or below the valve (subvalvular). Open-heart surgery is required for these types of stenoses and occasionally for valvular stenosis.

During the surgery, your doctor repairs the pulmonary artery or the valve to allow blood to pass through more easily. In certain cases, your doctor may replace the pulmonary valve with an artificial valve.

Some people with pulmonary stenosis have other congenital heart defects, and these may be repaired at the time of surgery. As with balloon valvuloplasty, there is a slight risk of bleeding, infection or blood clots associated with the surgery.

Preventive antibiotics
In the past, people with heart valve problems were advised to take antibiotics before certain dental and surgical procedures, to prevent bacteria from causing an infection of the inner lining of the heart (infective endocarditis).

The American Heart Association recently updated these recommendations, and antibiotics are no longer recommended for people who have only pulmonary stenosis. Instead, antibiotics are reserved for people at high risk of serious complications of infective endocarditis, such as those who have other heart conditions or artificial valves, or who've had repair with prosthetic material.

These new recommendations are based on evidence that random germs appear to cause infective endocarditis more frequently than do routine dental or medical procedures, and that widespread use of antibiotics carries a small risk of allergic reaction and may contribute to growing antibiotic resistance. A more effective preventive strategy may be to practice good oral hygiene and see your dentist for regular checkups.

If you've had your pulmonary valve replaced, you may still need preventive antibiotics before dental and other procedures. Talk to your doctor for specific recommendations in your case.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.