Bicuspid aortic valve

Definition

A bicuspid aortic valve is an aortic valve that only has two leaflets, instead of three.

The aortic valve regulates blood flow from the heart into the aorta, the major blood vessel that brings blood to the body.

Alternative Names

Bicommissural aortic valve

Causes, incidence, and risk factors

The aortic valve allows oxygen-rich blood to flow from the heart to the aorta. It prevents the blood from flowing back from the aorta into the heart when the pumping chamber relaxes.

Bicuspid aortic valve is present at birth (congenital). An abnormal aortic valve develops during the early weeks of pregnancy, when the baby's heart develops. The cause of this problem is unclear, but it is the most common congenital heart disease. It often runs in families.

The bicuspid aortic valve may not be completely effective at stopping blood from leaking back into the heart. This is called aortic regurgitation. The aortic valve may also become stiff and not open up as well, causing the heart to have to pump harder than usual to get blood past the valve (aortic stenosis). The aorta may become enlarged with this condition.

This condition is more common among males than females.

A bicuspid aortic valve often exists in babies with coarctation of the aorta and other diseases in which there is a blockage to blood flow on the left side of the heart.

Symptoms

Most of the time, bicuspid aortic valve is not diagnosed in infants or children because it causes no symptoms. However, the abnormal valve can leak or become narrow.

Symptoms of such complications may include:

• Baby or child tires easily
• Chest pain
• Difficulty breathing
• Rapid and irregular heartbeat (palpitations)
• Loss of consciousness (fainting)
• Pale skin

If a baby has other congenital heart problems, they may cause symptoms that will lead to the discovery of a bicuspid aortic valve.

Signs and tests

Signs of a bicuspid aortic valve may include:

• Enlarged heart
• Heart murmur
• Weak pulse in the wrists and ankles

Tests that may show a bicuspid aortic valve include:

• Magnetic resonance imaging (MRI) of the heart
• Ultrasound of the heart (echocardiogram)

If the health care provider suspects complications or additional heart defects, other tests may include:

• Chest x-rays
• Magnetic resonance imaging (MRI)
• Test of the electrical activity in the heart (electrocardiogram)
• X-ray of the heart's blood vessels using a special dye (angiography)

Treatment

The infant may need surgery to repair a leaky or narrowed valve, if complications are severe.

A narrowed valve can also be opened through cardiac catheterization. A fine tube (catheter) is directed to the heart and into the narrow opening of the aortic valve. A balloon attached to the end of the tube is inflated, to make the opening of the valve larger.

Critically ill babies with a severely narrowed valve may need medications. These medications improve the baby's condition so that either surgery or a balloon procedure is possible.

Medications may include:

• Drugs that make the heart muscle pump harder (inotropic agents)
• "Water pills" (diuretics)

Children with a bicuspid aortic valve are more likely to develop an infection inside the heart (endocarditis). Therefore, they must take antibiotics before undergoing dental treatments. Some children may not be able to exercise or participate in strenuous activities because of the valve.

See also: Pediatric heart surgery

Support Groups

Expectations (prognosis)

How well the baby does depends on whether complications of bicuspid aortic valve are present, and how severe they are.

The presence of other physical problems at birth also can affect how well a baby does.

Most babies with this condition have no symptoms, and the problem is not diagnosed until they are adults. Some people never find out that they have this problem.

Complications

Complications of bicuspid aortic valve include:

• Congestive heart failure
• Leakage of blood through the valve back into the heart
• Narrowing of the valve's opening

Calling your health care provider

Call your health care provider if your baby:

• Has no appetite
• Has unusually pale or bluish skin
• Seems to tire easily

Prevention

Bicuspid aortic valves run in families. If you know of this condition in your family, speak to your health care provider before becoming pregnant. There is no known way to prevent the condition.

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References

Otto CM, Bonow RO. Valvular Heart Disease. In: Braunwald E, Zipes DP, Libby P, Bonow R. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 62.

Park MK. Park: Pediatric Cardiology for Practitioners. 5th ed. Philadelphia, PA: Mosby Elsevier; 2008.