Acute Mitral Papillary Muscle Rupture Secondary to Cardiac Amyloidosis.

Acute mitral valve regurgitation due to papillary muscle rupture secondary to cardiac amyloidosis is rare. A 75-year-old woman without prior heart disease or chest trauma presented with acute mitral regurgitation and shock. Coronary angiography demonstrated patent coronary arteries. Emergency surgery revealed a prolapse of the anterior leaflet with posteromedial papillary muscle rupture. Mitral valvuloplasty was performed using artificial chordae and an annuloplasty ring. Histopathologic examination of the ruptured papillary muscle confirmed amyloid deposition between the cardiomyocytes. This case underscores the importance of cardiac amyloidosis in the differential diagnosis of patients with papillary muscle rupture without coronary artery stenosis.