Bicuspid Aortic Valve

Bicuspid aortic valve is a type of abnormality in the aortic valve in the heart. In bicuspid aortic valve, the valve has only two small parts (leaflets), instead of the normal three. This condition can be present from birth (congenital). In some cases, a person can have three leaflets but two leaflets become fused together over time. This is a condition called functional bicuspid valve. It can occur with other heart defects.

The heart’s ventricles are the two lower chambers of the heart. The left ventricle pumps oxygenated blood to the body. It connects to the aorta, the main blood vessel leading to the body. Between the left ventricle and the aorta is the aortic valve, one of the heart’s four valves. These valves help the blood flow through the heart’s four chambers and out to the body or into the lungs.

The aortic valve normally has three small parts, called leaflets. Sometimes, two leaflets develop instead of three. These leaflets may be thicker and stiffer than normal, too. That may cause aortic stenosis. In aortic stenosis, the valve won’t open as easily as it should when the heart squeezes. The left side of the heart has to work much harder than it normally would to get blood out to the body. Over time, this can damage the heart muscle.

Sometimes, the bicuspid aortic valve is leaky. This lets blood flow back into the heart when the heart relaxes, instead of flowing forward into the body the way it should. This process is called aortic regurgitation. It can also make the heart work harder.

Only a small portion of people have a bicuspid aortic valve. But it's one of the most common heart defects present from birth. It's also more common in boys than in girls.

No one knows exactly what causes most cases of bicuspid aortic valve. Researchers think that some types of inherited disorders can be linked to bicuspid aortic valve disease. Somehow, the valve doesn't develop normally before birth.

Bicuspid aortic valve tends to run in families. So it may result from a gene defect. Experts advise that parents, brothers, sisters, and children (first-degree relatives) of someone who has a bicuspid aortic valve be evaluated with an echocardiogram. Identifying and keeping track of the condition may help lower the risk for possible complications in the future. Researchers are still trying to learn more about the specific genes involved. It might also happen if a mother is exposed to certain infections or medicines while pregnant.

Certain factors can make acquired bicuspid aortic valve more likely to have problems. Some of these are:

• High cholesterol levels
• High blood pressure
• Smoking
• Chronic kidney disease

Some babies with very narrow aortic valves might have symptoms early on. Most of these valves work well for many years, though. There might not be any symptoms. Or symptoms may not appear until adulthood. Many times, people may not even realize they have a bicuspid aortic valve until they have it diagnosed as adults. Most commonly, people start to have symptoms some time in middle age.

Over time, the valve can become harder to open. Or it can become leakier. Symptoms can gradually develop. They may include:

• Shortness of breath with exercise
• Chest pain
• Lightheadedness or fainting
• Unable to exercise or loss of stamina
• Tiredness (fatigue)

These symptoms may look like other health problems. Always see your healthcare provider for a diagnosis.

Your healthcare provider will ask about your symptoms and past health. You will also need a physical exam. Some tests can also help with the diagnosis. These include:

• Echocardiography. This is the most important test. It shows the movement of blood through the valve using ultrasound.
• Transesophageal echocardiography. This is a heart ultrasound done from the esophagus that can give better pictures of the aortic valve.
• Electrocardiogram. This is done to check the heart’s electrical rhythm.
• Chest X-ray. These help view the heart anatomy and lungs.
• Cardiac CT or MRI. These are done if more detail is needed about the valve, heart, or aorta.

Sometimes, bicuspid aortic valve first appears on an echocardiogram done for other reasons. A cardiologist might first diagnose it.

Your healthcare provider may choose to keep track of you with periodic echocardiograms or MRIs. If your valve disease is more severe, they might need to do this testing as often as once a year.

Currently, there are no treatments known to prevent bicuspid valve from developing stenosis or regurgitation. Medicines for high blood pressure or high cholesterol may help some people.

If you have symptoms, your healthcare provider may recommend repairing or replacing the valve. That is the only certain treatment. Some people have this done during childhood. But other people may not need it until adulthood.

Your healthcare provider might recommend opening the valve with a procedure using a long, thin tube (catheter). This tube is threaded through a blood vessel all the way to the aortic valve. There a balloon can be inflated to open the valve. This is called valvuloplasty. This often is only a temporary measure. In most advanced cases, your healthcare provider might recommend open heart surgery. The aortic valve can then be replaced or fixed. Some people with bicuspid aortic valve may be able to have TAVR (transcatheter aortic valve replacement). This procedure uses a catheter instead of surgery to replace the valve.

Healthcare providers may use donor valves from cadavers for valve replacement. But most of the time, biologic valves made from tissue from a cow or a pig are used. Other times, they use artificial mechanical valves. Some artificial valves require you to take blood thinners lifelong. Sometimes surgeons replace the bicuspid aortic valve with the person’s own pulmonary valve and use a donor valve to replace the pulmonary valve. Each type of procedure and surgery has its own risks and benefits. Talk with your healthcare provider about what makes sense for you.

If you are pregnant or considering becoming pregnant, talk with your healthcare provider about treatment. You may need treatment even if you don’t usually have symptoms.

An untreated bicuspid aortic valve can eventually lead to symptoms of heart failure. These include shortness of breath, fatigue, chest pain, fainting, and swelling. Also, an aortic aneurysm might develop downstream from the aortic valve and can lead to bleeding or rupture. Healthcare providers prefer to treat bicuspid aortic valve before heart failure develops.

Endocarditis is another possible complication. It’s an infection of the heart valves. Your healthcare provider may give you special instructions about how to help prevent it.

People with bicuspid aortic valve can also have abnormal heart rhythms (arrhythmias) like atrial fibrillation. In rare cases, some arrhythmias can cause sudden death. That may be more likely to happen after exercise.

Your healthcare provider may give you other instructions for managing your bicuspid aortic valve and any other existing heart disease. These might include:

• Eating a heart-healthy diet
• Maintaining a healthy weight
• Exercising regularly (ask if you have any restrictions)
• Taking medicine for high cholesterol or high blood pressure if needed
• Not smoking
• Reducing stress
• Practicing good dental hygiene
• Controlling blood sugar levels if you have diabetes

If you have had a valve replacement, you may also need to take antibiotics before certain medical and dental procedures. Ask your healthcare provider if this applies to you. Some people will also need to take lifelong medicine to prevent blood clots.