Statistics from Altmetric.com
A 68 year old man presented with an acute non-Q wave anterolateral myocardial infarction. He initially made an uneventful recovery. On day 6 postinfarction he developed sudden onset pulmonary oedema with associated hypotension. He required immediate intubation and despite high level inotropic support he remained hypotensive. A systolic murmur was noted and an urgent transoesophageal echocardiogram was performed (top, transgastric view; MV, mitral valve; LV, left ventricle; LA, left atrium). This showed torrential mitral regurgitation secondary to a flail anterior mitral valve leaflet. The ruptured anterolateral papillary muscle could be identified attached to the leaflet via its chordae (arrowhead).
An intra-aortic balloon pump was inserted and coronary angiography performed. This revealed significant lesions in the left anterior descending (LAD) and right coronary arteries (RCA). At surgery the anterior mitral leaflet was confirmed to be flail but with chordae attached. The anterolateral papillary muscle had infarcted and torn off at the attachment to the ventricular wall (bottom, note the irregular discolouration of the infarcted muscle tip). The entire anterior leaflet was excised and replaced with a St Jude prosthesis. Vein grafts were placed on the LAD and RCA. He was discharged 10 days later.
Papillary muscle rupture is a rare but often fatal complication of myocardial infarction. Posteromedial papillary muscle involvement occurs more commonly than anterolateral papillary muscle involvement. These are usually secondary to full thickness inferior and anterolateral infarctions, respectively. Complete transection of a muscle causes catastrophic mitral regurgitation and is usually fatal.