"The valves between the chambers of the heart control the direction in which blood travels, and in particular, keep it from flowing backwards," explains Bridgeport Hospital–affiliated cardiovascular surgeon M. Clive Robinson, MD, an internationally-known expert in minimally invasive heart surgery.

Mitral valve prolapse is a condition in which the flaps of the mitral valve between the upper and lower chambers of the heart don’t work well. Result: Some of the blood sloshes back and forth between the two chambers instead of flowing steadily onward to the body. Most people with mitral valve prolapse don’t need any treatment because the condition is usually mild and has no serious effects.