Overview of pulmonary stenosis
Pulmonary stenosis is a congenital defect that occurs during the first eight weeks of pregnancy due to abnormal development of the prenatal heart.
The pulmonary valve appears between the right ventricle and the pulmonary artery. It has three leaflets that act as a one-way gate that allows blood to flow into the pulmonary artery, but not into the right ventricle.
With pulmonary stenosis, problems with the pulmonary valve make it difficult for the leaflets to open and allow blood to flow normally from the right ventricle to the lungs. In children, these problems include:
- Valve containing partially fused leaflets.
- Valve with thick leaflets that do not open all the way.
- The area above or below the pulmonary valve is narrow.
There are four types of pulmonary stenosis:
- Gluttonous pulmonary stenosis. Valve leaflets are thick and/or narrow.
- Supravalver pulmonary stenosis. The pulmonary artery above the pulmonary valve is narrow.
- Subvolver (infundibular) pulmonary stenosis. The muscle below the valve area thickens, narrowing the outlet of the right ventricle.
- Peripheral pulmonary branch stenosis. The right or left pulmonary artery may be narrow.
What happens in pulmonary valve stenosis
One or more of the cusps may be defective or too thick, or the cusps may not separate from each other properly. If this happens, the valve doesn’t open correctly, restricting blood flow.
Symptoms of pulmonary stenosis
The following are common symptoms of pulmonary stenosis. However, each child may experience symptoms differently. Symptoms can include:
- Heavy or rapid breathing
- Difficulty breathing
- High heart rate
- Swelling of the feet, ankles, face, eyelids and/or abdomen.
The symptoms of pulmonary stenosis are similar to those of other medical conditions or heart problems. Always consult your paediatrician for a diagnosis.
Causes of pulmonary stenosis
Pulmonary valve stenosis occurs when the pulmonary valve does not grow properly during fetal development. Babies with this condition can also have other congenital heart defects. It is not known what caused the abnormal development of the valve.
Normal pulmonary valve anatomy
The pulmonary valve is made up of three thin pieces of tissue called cusps that are arranged in a circle. With each heartbeat, the valve opens in the direction of blood flow into the pulmonary artery and continuing to the lungs then closes to prevent blood from flowing backwards into the heart’s right ventricle.
Pulmonary stenosis risk factors
Since pulmonary valve stenosis usually develops before birth, there are not many risk factors. However, certain conditions and procedures can increase the risk of pulmonary valve stenosis later in life:
- Carcinoid syndrome
- Rheumatic fever
- Noonan syndrome
- Pulmonary valve replacement
Pulmonary valve stenosis is often diagnosed in childhood, but sometimes it isn’t detected until later in life. If your doctor hears a heart murmur during a routine checkup and suspects pulmonary stenosis, he or she may then use a variety of tests to confirm the diagnosis.
- Sound waves bounce off your heart and produce moving images that can be viewed on a video screen. This test is useful for checking the structure of the pulmonary valve, the location and severity of the narrowing (stenosis), and right ventricle size and function. Doctors may also perform a 3-D echocardiogram.
- Cardiac catheterization. During this procedure, your doctor inserts a thin, flexible tube (catheter) into an artery or vein in your groin and threads it up to your heart or blood vessels. Dye injected through the catheter makes your blood vessels visible on X-rays. Doctors also use cardiac catheterization to measure the blood pressure in the heart chambers and blood vessels.
How is pulmonary stenosis treated?
In some cases, pulmonary stenosis does not require treatment. Medicines can sometimes treat symptoms. In severe cases, the pulmonary valve may need to be repaired or replaced.
A variety of procedures can repair or replace the pulmonary valve. Very severe cases of pulmonary stenosis can be treated with balloon valvuloplasty during cardiac catheterization. With this procedure, a doctor inserts an unopened balloon through the pulmonary valve and lifts it to open the valve.
Valve replacement installation involves the use of an artificial valve or a donor valve.
To determine which treatment to use, doctors consider:
- The age of the child.
- How well the other heart valves are working
- Have you had children before heart surgery?
- Do the children have other medical conditions?
Lifestyle and home remedies
While there’s little you can do to prevent pulmonary valve stenosis, you can take steps to ensure you won’t develop complications of your condition. Your doctor will also likely recommend regular follow-up appointments to evaluate your condition.
In most cases, you won’t need to take antibiotics to prevent an infection of the inner lining of the heart (infective endocarditis). Your doctor will recommend antibiotics if you’ve had endocarditis before or if you’ve had a pulmonary valve replacement.
Pulmonary stenosis is associated with the following:
- People with heart valve problems, such as pulmonary stenosis, have a higher risk of bacterial infection of the lining of the heart (infective endocarditis) than people without heart valve problems.
- Heart pumping problems. In acute pulmonary stenosis, the right ventricle of the heart must be pumped hard to force blood into the pulmonary artery. The pumping of the right ventricle against the increased pressure causes the muscle wall of the ventricle to stiffen (right ventricular hypertrophy). Over time, the heart can become hard and weak.
- Heart failure. If the right ventricle doesn’t pump efficiently, heart failure can develop. It can cause swelling of the legs and abdomen and can cause fatigue and shortness of breath.
- Irregular heartbeat (arrhythmia). People with pulmonary stenosis are more likely to have irregular heartbeat. The irregular heartbeat associated with pulmonary stenosis is generally not fatal unless the stenosis is severe.