We describe an unusual case of acute myocardial infarction of the non-dominant left circumflex artery, which resulted in posterior papillary muscle rupture. A 50-year-old man with a history of hypertension presented with acute chest pain, dyspnoea and massive haemoptysis for 1 day. The patient’s blood pressure was 100/80 mmHg and heart rate was 130 beats per minute. Physical examination revealed holosystolic murmur at the apex, and chest X-ray showed pulmonary oedema. Emergent cardiac catheterization showed thrombotic occlusion of an obtuse marginal artery, right dominance, and 70% stenotic lesion on the left anterior descending (LAD) artery. An echocardiogram showed severe mitral regurgitation with suspicious papillary muscle rupture, mild pulmonary hypertension and ischaemic insult on the territory of left circumflex artery. An intra-aortic balloon pump was placed, and on-site percutaneous coronary intervention on the LAD and obtuse marginal were done successfully, and the patient was transferred to the operating room for acute mitral regurgitation ( Fig. 1 ). During the operation, complete rupture of the posteromedial papillary muscle rupture was confirmed, with no other areas of necrosis. The patient underwent mitral valve replacement with bioprosthesis. The patient’s course was uncomplicated and he remains in New York Heart Association class II heart failure at 6-month follow-up.
