A bicuspid aortic valve has two leaflets, instead of three.
The aortic valve sits at the top of the heart where the blood exits to travel to the brain and body. A normal aortic valve is tricuspid, meaning it is formed from three separate leaflets. In some individuals, the valve is malformed from birth, and two of the leaflets are fused together (bicuspid, or two leaflets total). This congenital heart valve disorder affects both the aortic valve and the aorta, the great vessel attached to the aortic valve.
Bicuspid aortic valves have a tendency to deteriorate with time. The valve can become stenotic, meaning it is thickened and calcified, obstructing the blood flow out of the heart. The valve can also be insufficient, meaning it allows blood to leak back into the heart because the leaflets do not perfectly meet. As the valve deteriorates, the heart must perform extra work to pump the blood the body needs.
Importantly, the aorta of an individual with a bicuspid aortic valve is weaker that normal. The portion of the aorta directly above the valve, called the “ascending aorta”, has a higher likelihood of developing an aortic aneurysm or dissection. It is estimated that a person with a bicuspid valve has nearly a ten-fold risk of aortic dissection.
Many patients do not experience symptoms during childhood and do not find out about the bicuspid valve until they are adults. Bicuspid aortic valve can be identified during a physical examination where the doctor hears a heart murmur.
Bicuspid aortic valve can run in families, and it is recommended that family members of individuals with a bicuspid valve also undergo some type of screening. This may include a visit with an adult congenital heart specialist, advanced imaging, or both.
Detecting and Diagnosing Bicuspid Aortic Valve
The best test to evaluate bicuspid aortic valve is an echocardiogram. This test can also look at a portion of the ascending aorta to determine if there is an associated aneurysm.
An echocardiogram (echo for short) is a cardiac ultrasound that helps assess heart conditions.
Treatments for Bicuspid Aortic Valve and Associated Aneurysm
Aneurysms associated with bicuspid aortic valves have a higher risk of dissection than others. Thus, surgical intervention is often recommended earlier in these patients.
Patients with aortic stenosis may need this heart surgery to repair or replace their aortic valve.
Thoracic aortic aneurysm repair is a surgery that repairs a weakened area of the aorta.