|Pulmonary Valve Stenosis
Pulmonary valve stenosis is a narrowing of the pulmonary valve, the flap that separates the lower right chamber (right ventricle) of your heart from the pulmonary artery. During circulation, oxygen-poor blood returning from your body is pumped from your heart, through the pulmonary valve and into the pulmonary artery, which carries the blood to your lungs to pick up oxygen and drop off carbon dioxide. If the pulmonary valve is constricted (stenosed), your heart has to pump harder to push blood through the valve and into the pulmonary artery.
The disorder is usually present since birth (congenital). It's one of the more common heart birth defects, with the majority of the cases being mild. Pulmonary valve stenosis occurs in about one of 10 children, and females are slightly more likely to be affected than males. Adults occasionally have pulmonary valve stenosis as a complication of another illness.
Pulmonary valve stenosis ranges from mild and without symptoms to severe and debilitating. While mild pulmonary stenosis doesn't usually worsen over time, moderate and severe cases may progress and require surgery. Fortunately, treatment is highly successful, and most people with the condition can expect to lead normal lives.
Pulmonary valve stenosis usually occurs due to improper development of the pulmonary valve during fetal growth. 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) and supravalvular (above the valve). Pulmonary stenosis can also occur at more than one
location. The most common type of pulmonary stenosis is valvular.
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. In valvular pulmonary 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.
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.
Risk Factor :
Pulmonary stenosis is hard to prevent because the majority of people who have this disorder are born with it. Certain conditions, including carcinoid syndrome or rheumatic fever, can increase your risk for pulmonary stenosis.
When to seek medical advice :
If you or your child experience symptoms of shortness of breath, fainting or chest pain, you should talk to your doctor. If you do have pulmonary stenosis or another heart problem, prompt evaluation and treatment can help reduce your risk of complications.
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)
- A bluish coloration of the skin caused by blood low in oxygen (cyanosis)
- 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.
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 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.
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.
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 stenosed. 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.
How balloon valvuloplasty works
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. 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. Fortunately, serious complications are rare and most people can expect to return to normal activity afterwards.
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 patients 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.
Most of the time, pulmonary stenosis can't be prevented because it's typically present at birth or arises later as the result of another condition. If you do have pulmonary stenosis or other valve disorders, it's important that you take steps to prevent endocarditis. Here are a few tips to help reduce your risk :
- If you contract strep throat or scarlet fever, seek treatment immediately.
- If your child is undergoing certain medical or surgical procedures, such as dental cleanings or tooth extractions, he or she should take antibiotics beforehand.
- If you're pregnant, consider taking antibiotics during delivery.
If you or your child is diagnosed with pulmonary stenosis, keep this in mind: Whether you need surgery or just periodic checkups, pulmonary stenosis is a condition that can be well-managed with appropriate medical care.