Monday, August 24, 2009

Mitral Regurgitation

Mitral regurgitation is the abnormal blood backflow from the left ventricle back into the left atrium of the heart every time the left ventricle contracts to pump the blood out into the aorta artery during sistole. "Regurgitation" means "backflow". This heart condition is caused by mitral valve prolapse, which is the reversion of one or both of the mitral valve leaflets into the wrong side (the left atrium). If mitral regurgitation is severe, people have difficulties in breathing, but mild regurgitation might not need treatment. Severe regurgitation could cause the accumulation of fluid in the lungs. There are two types of mitral regurgitation: 1) chronic, which develops slowly as the person gets older; 2) acute mitral regurgitation, which develops quickly is often life-threatening.

The most common cause of primary mitral regurgitation is myxomatous degeneration of the valve, which is more common in males and in advanced age people. It is due to a genetic abnormality that results in a defect in the collagen that makes up the mitral valve. This causes a stretching out of the leaflets of the valve and the chordae tendineae. The elongation of the valve leaflets and the chordae tendineae prevent the valve leaflets from fully coapting when the valve is closed, causing the valve leaflets to prolapse into the left atrium, thereby causing mitral regurgitation.