Posterior myocardial infarction complicated by rupture of the posteromedial papillary muscle.

A 61-year-old man was admitted with acute posterior myocardial infarction and, on physical examination, was shown to have a mitral regurgitation (MR) murmur. Transthoracic echocardiography (TTE) showed severe hypokinesis of the posterior wall and severe MR by color flow. Right heart catheterization with a balloon-tipped catheter revealed a pulmonary artery wedge pressure of 30 mmHg. No 'step-up' was seen in blood samples from the right atrium and right ventricle. On angiography, a subtotal occlusion of the mid circumflex artery was found which was angioplastied and stented. As the patient's clinical condition did not improve, he underwent transesophageal echocardiography (TEE) for further evaluation. This showed complete rupture of the posteromedial papillary muscle. The patient underwent urgent surgery with successful mitral valve replacement. The postoperative course was uncomplicated, and clinical improvement seen. This case report underscores the value of TEE in accurate preoperative diagnosis of papillary muscle rupture by providing preoperative anatomic details of the mitral valve apparatus and surrounding structures.