Mitral regurgitation is the leaking of blood from the left ventricle across the mitral valve, and into the left atrium. The flow of blood pumped by the heart is controlled by one-way valves. These valves assure that blood moves in only one direction. When the mitral valve leaks, some of the blood that should be pumped into the body instead goes backward into the left atrium. If the amount of blood that leaks is severe, mitral regurgitation can be a serious condition that requires care from your doctor. The sooner it is treated, the more favorable the outcome. If you suspect you have this condition, contact your doctor immediately.

Function of the Mitral Valve in the Heart
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© 2011 Nucleus Medical Media, Inc.

Mitral Valve Regurgitation
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© 2011 Nucleus Medical Media, Inc.

There are several causes for leaky heart valves. Birth defects can deform them. Infections can scar them. Heart attacks can damage them, and the mechanics of an enlarged heart can stretch out the opening so that the valve is no longer large enough to work effectively.

  • Rheumatic fever —infectious diseases of several kinds can afflict the inside of the heart, leading to scarring of the heart’s valves. Rheumatic fever used to be a common cause of mitral valve damage but is seen infrequently today in the United States.
  • Heart attack —inadequate blood supply to the heart can weaken the small muscles that hold the mitral valve in place, causing it to leak.
  • Congenital deformity—several different types of congenital heart defects distort the mitral valve.
  • Heart muscle disease—not only infections, but many other types of disease can weaken the heart muscle, stretching out the mitral valve ring so that the valve no longer closes. Among these causes are alcohol, certain drugs, radiation, muscular dystrophies, malnutrition, cancer, and a long list of inflammatory and metabolic disorders.
  • Mitral valve prolapse—abnormal closure of the valve with protrusion of a leaflet tip backward into the left atrium, causing it to leak. This may me congenital or acquired.