Anterolateral Papillary Muscle Rupture: A Rare Complication of Myocardial Infarction.

BACKGROUND: Myocardial infarctions can result in mechanical complications such as rupture of papillary muscles. Rupture of the anterolateral papillary muscle is rarer because of its dual blood supply. CASE SUMMARY: A 44-year-old man presented with subacute chest pain and was diagnosed with a non-ST-segment elevation myocardial infarction. Coronary angiography revealed multivessel coronary artery disease, for which the patient underwent urgent coronary artery bypass grafting to revascularize. Postoperatively, he developed acute respiratory failure due to pulmonary edema in the setting of decompensated heart failure. Echocardiography revealed rupture of the anterolateral papillary muscle, resulting in severe mitral regurgitation. The patient underwent emergent mitral valve replacement, after which he made a gradual recovery. DISCUSSION: Papillary muscle rupture is a rare but catastrophic mechanical complication of myocardial infarction that can present despite timely revascularization. This may occur in the anterolateral papillary muscle despite its dual blood supply. TAKE-HOME MESSAGE: In patients with severe multivessel disease, maintain a high level of vigilance for post-myocardial infarction mechanical complications occurring in infrequent anatomic locations.