Mitral insufficiency following myocardial infarction.

Severe mitral insufficiency following myocardial infarction in 15 patients is reported. The mean interval from infarction to surgery was 2.8 years. All patients were operated on with mitral valve replacement and in 14 aortocoronary bypass and/or resection of left ventricular aneurysm was necessary as well. Rupture of one or more heads of the papillary muscle was found in 5 patients. In another 5 the papillary muscles were discoloured, fibrosed and shortened, and in the last 5 patients the mitral incompetence was caused by a marked dilatation of the atrioventricular ring. Five patients (33%) died, 3 early and 2 late after surgery. All the patients who died had a markedly imparied left ventricular function pre-operatively with end-diastolic pressures from 15 to 26 mmHg.