The murmur of papillary muscle dysfunction in acute myocardial infarction: Clinical features and prognostic implications

Abstract

The systolic murmur of papillary muscle dysfunction is a well-recognized feature of acute myocardial infarction (AMI), but no large prospective studies have determined its incidence, associated variables, and prognostic implications. Of 1653 patients who entered our data base with MI, 283 (17%) were classified as having a systolic murmur suggesting mitral regurgitation. At hospital discharge, there was a 5% incidence. There was a higher incidence of systolic murmur in non-Q wave AMI than in inferior or anterior Q wave MI (24% vs 13% and 15%, p < 0.001). Advanced age, previous MI, and heart failure were all associated with systolic murmur ( p < 0.01). Persistent pain in the coronary care unit occurred more often in those with systolic murmur (45% vs 26%, p < 0.0001). Systolic murmur was associated with an S 3 and bibasilar rales ( p < 0.001) in the hospital; however, it was inversely related to peak cratine kinase and unrelated to heart failure or ejection fraction at discharge. Univariate predictors of mortality associated with systolic murmur included complex premature ventricular contractions at discharge and a non-Q wave location. Patients with systolic murmur had higher hospital and 1-year mortalities than those without systolic murmurs ( p < 0.01). When systolic murmur was present during hospitalization, the average time to reinfarction was 2.5 times earlier than when no systolic murmur was present (84 vs 214 days, p < 0.0001). Thus, although systolic murmur of papillary muscle dysfunction in MI appears transient in most cases, its presence is associated with prior infarction, persistent pain, heart failure, and greater mortality despite small infarct size. The presence of systolic murmur may also represent a subset of patients at high risk for early reinfarction.