Mitral regurgitation; acute

Alternative names:

acute mitral regurgitation; mitral insufficiency

Definition:

A disorder in which the mitral heart valve does not close properly, causing blood to leak (back-flow) into the left atrium when the left ventricle contracts.

Causes, incidence, and risk factors:

Regurgitation (leaking from insufficient valve closure) is caused by disorders that weaken or damages the valve. Inadequate closure of the mitral valve causes blood to backflow to the left atrium. The blood flow to the rest of the body is decreased because of the backflow. The heart may pump harder to try to compensate for the decreased blood flow to the body.

Acute mitral regurgitation may be the result of dysfunction or injury to the valve following MI or infective endocarditis. These conditions may result in rupture of the valve, papillary muscle, or chordae tendineae (the structures that anchor the valve cusps). A rupture of these structures results in the valve leaflet prolapsing (protruding) into the atrium, leaving an opening for the backflow of blood.

Risk factors include an individual or family history of the above disorders.

Mitral regurgitation (both acute and chronic mitral regurgitation) affects approximately 5 out of 10,000 people.