Heart valve leakage Mitral valve prolapse The heart has four valves that ensure that blood flows in the correct direction around the heart. Their function may be impaired by changes due to aging, infections such as endocarditis (infection of the heart lining) or rheumatic fever, or a heart attack; heart valve problems may also sometimes be present at birth. Stiffness of a valve (known as stenosis) prevents it from opening fully, restricting the blood flow.
Alternatively, a valve may be leaky—it does not close fully, and some blood leaks backward. Leakage is often due to a valve being floppy, a condition known as prolapse. In both cases, the heart has to work harder to pump blood around the body, which may eventually lead to heart failure; valve disorders also increase the risk of clots and stroke.
In mild cases, there may be no symptoms.