In chronic cases, most are normal variants if they are mild in degree. Pathological conditions are seen in: (1) valve damage due to rheumatic fever; (2) coronary artery disease; (3) mitral annulus calcification; (5) mitral valve prolapse; (4) left ventricular enlargement from any cause; and (6) congenital malformations, connective tissue disease, and hypertrophic obstructive cardiomyopathy. Acute cases are more often caused by tendon rupture, damaged or torn valves, papillary muscle insufficiency, necrosis or rupture, and dehiscence after prosthetic valve replacement, and can be seen in infective endocarditis, acute myocardial infarction, spontaneous tendon rupture, and chest trauma (including nonpenetrating).