Isolated acute anterolateral papillary muscle rupture presenting as a sole manifestation of acute myocardial infarction and mimicking mitral valve vegetation.

We present here a case of an acute myocardial infarction presenting solely as rupture of the head of anterolateral papillary muscle of the mitral valve with an echocardiographic appearance of a mitral valve vegetation. A 61-year-old male patient presented to the hospital with cardiogenic shock. Transesophageal echocardiography revealed normal left ventricular global and regional systolic function with the echocardiographic appearance of a large vegetation attached to the anterior mitral valve leaflet and severe mitral regurgitation. Intraoperatively, an infracted and ruptured head of the anterolateral papillary muscle was found with no evidence of vegetations. Papillary muscle rupture is a rare complication of acute myocardial infarction, is usually associated with inferior myocardial infarction and rarely seen as the only clinical and echocardiographic finding. Transesophageal echocardiography is more sensitive than transthoracic echocardiography but misdiagnosis can still occur.