Cardiac tamponade masking clinical presentation and hemodynamic effects of papillary muscle rupture after acute myocardial infarction.

A 67-year-old woman sustained an acute lateral-wall myocardial infarction and was treated with thrombolytic therapy. Postinfarction hypotension developed 3 days later. Clinical findings at that time were consistent with cardiac tamponade, and an echocardiographic study revealed a moderate-sized pericardial effusion. She underwent urgent pericardiocentesis with transient improvement in hemodynamics, followed by deterioration associated with the development of acute pulmonary edema. Follow-up transesophageal echocardiographic imaging revealed papillary muscle rupture with severe mitral regurgitation. The patient underwent urgent surgical intervention consisting of coronary artery bypass grafting and mitral valve replacement. The presence of cardiac tamponade in this patient masked the clinical manifestations of papillary muscle rupture through the hemodynamic effect of tamponade physiology on mitral regurgitation.