Left-Sided Heart Failure and Papillary Muscle Dysfunction

Abstract

Papillary muscle dysfunction is an extremely rare complication of acute myocardial infarction. Ischemic or necrotic lesions may impair one or two of the papillary muscles to such an extent that the anchoring function and closure of the mitral valves is no longer effective. Without shortening of the papillary muscles in systole, coaptation of valve leaflets anchored by the chordae tendineae is inadequate which leads to a gap in closure. The result is mitral insufficiency with a holosystolic murmur that is heard best at the cardiac apex and radiates into the axilla. Occasionally, only a late systolic murmur is found indicating that the papillary muscle functions in early systole but later demonstrates its ischemia-induced functional impairment in being unable to maintain the state of contraction to the end of systole.