Left ventricular function in acute non-ischaemic mitral regurgitation.

Acute non-ischaemic mitral regurgitation (MR) has recently generated considerable interest because of its causal relationship to ruptured chordae tendineae and infective endocarditis, advances in its diagnosis by echo Doppler studies, and its management by afterload reduction and reconstructive surgery. It is fundamentally different from chronic MR because the previously normal, unprepared left ventricle (LV) and left atrium (LA) confront a sudden dramatic increase in volume. As the normal-sized left atrium suddenly receives a marked regurgitant flow, its pressure rises and is transmitted into the pulmonary capillaries causing pulmonary congestion and oedema.