Acute severe mitral regurgitation. Pathophysiology, clinical recognition, and management.

Acute severe mitral regurgitation often goes unrecognized as an emergency requiring prompt, lifesaving treatment. Its causes, physical signs, natural history, echocardiographic features, and findings on chest roentgenography, electrocardiography, and nuclear scintigraphic scanning are reviewed. Acute severe mitral insufficiency can be differentiated from chronic severe mitral insufficiency by noninvasive two-dimensional echocardiography. M-mode echocardiography is a valuable tool in evaluating mitral prosthetic paravalvular regurgitation.