Bicuspid Aortic Valve Stenosis
What is bicuspid aortic valve stenosis?
See your doctor promptly if you have symptoms of bicuspid aortic valve stenosis. For chest pain and shortness of breath, seek immediate medical care (call 911) to rule out potentially life-threatening heart problems.
Bicuspid aortic valve is the most common type of congenital heart defect. It affects about 2% of the population and is 2 to 3 times more likely to occur in males than females. Normally, the aortic valve has three cusps—or leaflets. They open wide to let blood leave the left ventricle and enter the aorta. They close tightly afterwards to prevent blood from going backwards. A bicuspid aortic valve has only two leaflets because two of the three leaflets fuse during development. This deformity prevents the valve from working the way it should. In most cases, it becomes stenotic, meaning the opening is too narrow. Sometimes, the leaflets do not close properly. This results in regurgitation—or blood leaking back through the valve.
Bicuspid aortic valve occurs very early in development, during the first eight weeks of pregnancy. So, bicuspid valve stenosis is present at birth. However, most people live years without knowing anything is wrong. The defective valve can function for decades before symptoms develop. Only about 2% of children with the heart defect have bicuspid valve stenosis symptoms.
Like other heart valve defects, it is unclear exactly what causes bicuspid aortic valve. Doctors believe there is a significant genetic component to the defect. It often occurs along with other defects, such as coarctation of the aorta. There is also about a 10% risk of bicuspid aortic valve when a first-degree relative has it.
Symptoms of bicuspid aortic valve disease most commonly develop in middle age in people with a history of a childhood heart murmur. Common symptoms include chest pain, shortness of breath, dizziness and fainting. Most people require treatment once symptoms develop. Bicuspid valve stenosis treatment involves surgery to replace the valve. Options include mechanical or biological valves.
In stenosis of a bicuspid aortic valve, the left ventricle must work harder to get blood through the valve. In severe stenosis, this can cause enlargement of the heart muscle in the ventricle. Eventually, heart failure and other complications can occur.
What are the symptoms of bicuspid aortic valve stenosis?
These symptoms can mimic life-threatening conditions, such as heart attack. Seek immediate medical care (call 911) if you, or someone you are with, have any of these symptoms.
In most cases, symptoms of bicuspid aortic valve do not start until adulthood, even though stenosis is present at birth. A childhood heart murmur may occur without symptoms. As the valve ages, symptoms can appear. People are often in their 30s or 40s when they begin to have symptoms of bicuspid aortic valve stenosis. However, severe disease may cause symptoms in children. Mild disease may not cause symptoms until old age.
Common symptoms of bicuspid aortic valve
Common symptoms of bicuspid aortic valve disease include:
- Chest pain
- Dizziness or fainting
- Shortness of breath, especially with exertion
What causes bicuspid aortic valve stenosis?
Bicuspid aortic valve is a birth defect that develops in the first eight weeks of pregnancy. The reason for the abnormal development is unclear. However, there is likely a genetic component to it as it tends to run in families.
The defect occurs when two of the three valve leaflets fuse together during development. This results in two leaflets instead of three. The fused leaflets create a flap that is too large to function properly. Most commonly, this causes stenosis—or narrowing—of the valve opening, as the large flap is unable to fully open. The narrowed opening restricts the amount of blood that can pass through the valve. Since the aorta delivers freshly oxygenated blood throughout the body, bicuspid valve stenosis reduces the amount of oxygen to vital organs, including the heart and brain.
What are the risk factors for bicuspid aortic valve stenosis?
A bicuspid aortic valve deformity affects males three times more often than females. The other major risk factor for the defect is having a first-degree relative with a bicuspid aortic valve.
Reducing your risk of bicuspid aortic valve stenosis
It is not possible to definitively prevent bicuspid aortic valve disease because the exact cause is unknown. However, studies have shown that women who consume daily folic acid before and during pregnancy are less likely to deliver children with congenital heart abnormalities. Since genetics likely play a role, talk with your doctor if you have a first-degree relative with the defect. Current guidelines recommend screening for bicuspid aortic valve stenosis in this case.
How do doctors diagnose bicuspid aortic valve stenosis?
Sometimes, doctors find bicuspid aortic valve stenosis during a workup for another condition. If you have symptoms of bicuspid aortic valve disease, your doctor will likely start with a physical exam and questions. During a physical exam, your doctor may hear a heart murmur that suggests a problem with the aortic valve. The murmur occurs as a result of turbulent blood flow through the valve.
Questions your doctor may ask include:
- When did you first notice symptoms?
- When do your symptoms occur?
- Do your symptoms happen all the time or do they come and go?
- What, if anything, seems to make your symptoms better or worse?
- Did you have a heart murmur as a child?
- Does anyone in your family have heart valve problems?
If your doctor suspects a heart valve problem, testing will be necessary. The main tool for diagnosing bicuspid aortic valve stenosis is an echocardiogram. This test makes moving images of the heart using sound waves. Doctors can take these images from outside on your chest or by putting a small device down your esophagus (TEE or transesophageal echocardiogram).
What are the treatments for bicuspid aortic valve stenosis?
For known cases of bicuspid aortic valve stenosis, care and monitoring by a cardiologist is a lifelong necessity. However, many people live for decades before realizing there is a problem. About 80% of people with this heart defect will need surgery to correct it. Most often, treatment becomes necessary during middle age, in the 30s and 40s. Surgery may also be necessary to repair any problems with the aorta.
The main bicuspid aortic valve stenosis treatment is valve replacement. There are two types of replacement valves—biological and mechanical. Biological valves can come from cows, pigs or humans. These valves will degrade with time and usually require another replacement. Mechanical valves are more long-lasting, but they require lifelong anticoagulant medicines (blood thinners). Seeking the advice of a specialist in bicuspid aortic valve disease can help you understand the best option for you.
In infants and children, balloon valvuloplasty can be successful. This catheter-based procedure uses a balloon to stretch the valve opening. It tends to be unsuccessful in adults because their valves are often calcified and stiff. The valve usually narrows again in adults. Aortic valve replacement in adults may be performed with open heart surgery or with a specialized cardiac catheter, known as transcatheter aortic valve replacement (TAVR).
Self-care for bicuspid aortic valve stenosis
Anyone with valve disease can benefit from a heart-healthy lifestyle. It may help prevent other heart problems and complications. Living heart-smart includes:
- Eating a heart-healthy diet, including whole grains, low-fat dairy, lean meats, and fresh fruits and vegetables
- Getting regular physical activity
- Maintaining a healthy weight
- Not smoking
Ask your doctor for guidance before making significant changes to your diet or exercise program.
What are the potential complications of bicuspid aortic valve stenosis?
About 30% of people with a bicuspid aortic valve defect will eventually develop complications. Seeing a cardiologist for regular monitoring can help identify problems early, before they become life-threatening. Potential complications of bicuspid aortic valve stenosis include:
- Aortic aneurysm and dissection, which happens when the tissue in the walls of the aorta degenerates. An aneurysm is a weakening and thinning in the wall, causing a bulge that can rupture. A dissection occurs when the layers of the wall shred apart. Both are potentially fatal emergencies. This complication is likely related to an underlying connective tissue disorder that occurs in people with bicuspid aortic valve.
- Endocarditis, which is an infection of the lining of the heart
- Heart failure, which results from enlargement of the left ventricle. This thickening of the heart muscle happens when the ventricle must work too hard to pump against the resistance of the valve. With time, the ventricle weakens and is unable to pump efficiently.
Does bicuspid aortic valve stenosis shorten life expectancy?
Most cases of bicuspid aortic valve stenosis are not diagnosed until adulthood. Sometimes, doctors do not find it until older adulthood when people are in their 60s or 70s. But most often, the diagnosis comes during middle age. Surgical treatment is highly successful in the hands of expert surgeons at specialized heart centers. Recent research suggests adults who receive treatment for bicuspid valve stenosis have the same life expectancy as the general population.