Bicuspid Aortic Valve Disease Causes, Symptoms, Diagnosis, Treatment

Bicuspid Aortic Valve Disease Causes, Symptoms, Diagnosis, Treatment

What is bicuspid aortic valve disease?

The aortic valve is a one-way valve between the heart and the aorta, the main artery from the heart that distributes oxygen-rich blood to the body. Normally, the aortic valve has three small flaps or leaflets that open widely and close securely to regulate blood flow, allowing blood to flow from the heart to the aorta and preventing blood from flowing backwards into the heart.

In bicuspid aortic valve disease, the valve has only two leaflets. With this deformity, the valve doesn’t function perfectly, but it may function adequately for years without causing symptoms or obvious signs of a problem.

The latest studies suggest that bicuspid aortic valve disease is caused by a connective tissue disorder that also causes other circulatory system problems. People with bicuspid aortic valve disease also may have abnormal coronary arteries, aortic aneurysm or an abnormal thoracic aorta (the portion of the aorta that passes through the upper chest) and unstable (labile) high blood pressure.

Types of Bicuspid Aortic Valve Disease

There are two types of Bicuspid Aortic Valve Disease that can cause stress to a person's heart. Bicuspid aortic valve insufficiency occurs when the aortic valves do not close as tightly as they should. The weak, or insufficient valves allow blood back into the heart, a condition called regurgitation or leakage. Regurgitation, due to a weakened bicuspid valve, puts additional strain on the heart because the muscle must work harder to re-pump the blood out to the body. Insufficiency of this kind can be repaired through surgery, but sometimes is not successful if the leakage has been going on for a long period of time.

Bicuspid aortic valve stenosis is the narrowing of the deformed valve. Deposits of calcium may make the valves smaller than normal, and unable to open as fully as a normally formed aortic valve. Additional stress is placed on the heart's left ventricle as it works overtime to pass blood through the narrowed valves. The Bicuspid Aortic Foundation (BAF) explains that people with early bicuspid aortic valve stenosis may feel the strain during physical exertion, but not during periods of rest.

What causes bicuspid aortic valve disease?

The actual cause of bicuspid aortic valve disease is not completely clear. We do know that the two-leaflet valve develops in the early stages of pregnancy, and the defect is present at birth. About 2% of the population has Bicuspid Aortic Valve Disease, and it is twice as common in males as in females.

What are the symptoms and signs of Bicuspid Aortic Valve Disease?

Although bicuspid aortic valve disease is present at birth, it usually is not diagnosed until adulthood because the defective valve can function for years without causing symptoms. Rarely, the disease is so severe at birth that the baby develops congestive heart failure early in life. More commonly, patients will have a history of having a childhood murmur and symptoms develop in mid-life as the valve ages.

Calcium deposits on and around the leaflets eventually cause the valve to stiffen and narrow, a condition known as stenosis. As stenosis develops, the heart must pump increasingly harder to force the blood through the valve. Symptoms of a stenotic valve include chest pain, shortness of breath and dizziness or fainting caused by inadequate blood flow to the brain.

If the bicuspid valve does not close completely, blood can flow backwards into the heart. This is regurgitation, also called aortic valve insufficiency. The heart then must pump that same blood out again, causing strain on the heart’s lower left chamber, the left ventricle. Over time, the ventricle will dilate, or over-expand. The main symptom of aortic valve regurgitation is shortness of breath during exertion, like walking up stairs.

As the disease progresses, these symptoms start occurring more frequently, even without exercise. When a physician listens to the person's heart, characteristic murmurs can be heard.

How is bicuspid aortic valve disease diagnosed?

Individuals experiencing symptoms such as shortness of breath typically begin with their family doctor, who will perform a physical examination that includes listening to the person's heart. When the patient’s symptoms and the sounds heard on the cardiac exam raise the suspicion of bicuspid aortic valve disease, the patient needs to be referred to a specialist in valvular heart disease.

Bicuspid Aortic Valve Disease is diagnosed mainly though imaging testing. The BAF reports that some physicians may be able to detect regurgitation when listening to a patient's chest through a stethoscope, but this is not always a reliable diagnostic tool. CAT scans, ultrasounds and magnetic resonance imaging (MRI) may all be used to identify the shape of the heart's valves and to determine the damage that may have resulted from this congenital defect.

What is the treatment for Bicuspid Aortic Valve Disease?

Bicuspid Aortic Valve Disease may be treated through medication and surgery. Medications such as ACE inhibitors and beta blockers are prescribed to lower blood pressure and reduce leakage. Self-care measures are recommended in conjunction with medical intervention and include following a healthy diet and exercise plan to reduce the risk of further heart disease. Weight lifting is not recommended as a form of exercise because of the undue strain that is placed on the aortic valve.

Valve replacement surgery may be performed to counter the damage sustained from a bicuspid aortic valve. Valves that do not need to be completely replaced may be repaired in order to correct stenosis, or the narrowing of the valve.

Prevention of Complications

People with Bicuspid Aortic Valve Disease are more susceptible to infection and must take precautions to avoid complications that can become dangerous to their health. Patients with heart valve defects should take antibiotics prior to routine tooth cleaning appointments as well as extensive dental work to prevent infection. Minor medical procedures, such as biopsies or the removal of a mole, should also be treated with a preventive dose of antibiotic medications.