bicuspid aortic valve

A normal aortic valve has three little cup-shaped flaps (cusps) that together seal the exit from the heart. In a bicuspid aortic valve a person is born with only two cusps instead of three — often because two of them are fused. It is one of the most common congenital heart conditions, present in roughly one to two people in a hundred.

Two cusps doing the work of three is a less efficient and more stressed design. Over decades the valve tends to wear, stiffen, and calcify faster than a normal valve, so bicuspid valves are an important cause of aortic stenosis appearing at a relatively young age, and they can also leak (regurgitation). Many people, however, have no trouble for years.

Importantly, a bicuspid valve is more than a valve issue: it is associated with weakness and widening of the aorta (aortic dilation or aneurysm), which carries its own risks and is monitored over time. Because it can run in families, relatives are sometimes screened. Diagnosis is by echocardiography, with the aorta followed by imaging.

A bicuspid aortic valve warrants lifelong surveillance of both the valve and the aorta; this entry gives general background, not an individual care plan.