Bicuspid aortic valve
The aortic valve is the valve between the heart’s main pumping chamber (the left ventricle) and the aorta, which carries oxygenated blood to the brain and body. The aortic valve normally has three leaflets (flaps) that serve as a one-way valve to allow blood through to the aorta and prevent it from leaking back into the pumping chamber.
Bicuspid aortic valve refers to aortic valves that have only two leaflets. Over time, the valve can become stenotic, resulting in varying degrees of obstruction across the valve. Additionally, the valve may begin to leak. The left ventricular function may be impaired with deterioration of valve function. The ascending portion of the aorta may also dilate. Usually, the diagnosis of a bicuspid aortic valve is made secondary to the presence of a cardiac murmur or in combination with other defects such as coarctation (narrowing) of the aorta.
Bicuspid aortic valve is a common congenital condition that often runs in families. Early in a pregnancy, as the fetus’s heart develops, an abnormal aortic valve develops. The cause of this condition is unknown.
Bicuspid aortic valve often is not diagnosed in infants or children because it usually is asymptomatic. Signs of a bicuspid aortic valve may include:
- Enlarged heart
- Heart murmur
- Weak pulse in the wrists and ankles
If the abnormal valve leaks or becomes narrow, complications will have symptoms such as:
- Baby or child tiring easily
- Chest pain
- Difficulty breathing
- Rapid and irregular heartbeat (palpitations)
- Pale skin
- Leakage of blood through the valve back into the heart
- Narrowing of the valve's opening
- Congestive heart failure
Other congenital heart problems may cause symptoms that will reveal a bicuspid aortic valve.
A bicuspid aortic valve often exists in babies who have coarctation of the aorta and other diseases where there is a blockage to blood flow on the left side of the heart. Bicuspid aortic valve is more common in males than in females.
Patients with Turner syndrome (a congenital syndrome affecting females that often includes major heart defects) have an increased incidence of bicuspid aortic valve.
Tests that may show a bicuspid aortic valve include:
- Magnetic resonance imaging (MRI) of the heart
- Ultrasound of the heart (echocardiogram)
If your healthcare provider suspects complications or additional heart defects, other tests may include:
- Chest X-rays
- Test of the electrical activity in the heart (electrocardiogram)
- X-ray of the heart's blood vessels using a special dye (angiography)
Treatment of mild to moderate stenosis includes medical management of blood pressure, heart failure (if present) and observation and serial evaluation of the pressure across the stenotic valve. In moderate to severe stenosis, balloon angioplasty replacement may be considered instead of valve replacement.
If only regurgitant lesions are present (aortic insufficiency), serial follow-ups of left ventricular function and dimensions with aortic valvuloplasty and/or replacement are possible options.
Aortic root dilatation can occur with bicuspid aortic valves. This would be followed serially with aortic root/ascending aorta replacement as a surgical option. If complications are severe, an infant or child may need surgery to repair a leaky or narrowed valve. A narrowed valve also can be opened through cardiac catheterization.
Medications may be prescribed to relieve symptoms or prevent complications. The condition may require lifelong surveillance. In some cases, the bicuspid aortic valve needs to be replaced with a bioprosthetic or mechanical valve.
There is no known way to prevent the condition, but if bicuspid aortic valves run in your family, consult your healthcare provider before becoming pregnant.
A baby’s condition after a procedure depends on whether complications of bicuspid aortic valve are present, and how severe they are. Other congenital problems also may affect the child’s condition.