RUPTURE OF THE INTER-VENTRICULAR SEPTUM COMPLICATING MYOCARDIAL-INFARCTION - PATHOLOGICAL ANALYSIS OF 10 PATIENTS WITH CLINICALLY DIAGNOSED PERFORATIONS

Among 768 myocardial infarcts in 480 hearts studied after postmortem coronary arteriography and formalin fixation in a distended state, there were 10 infarcts (1.3 per cent) complicated by perforation of the interventricular septum. Infarcts with rupture were large (average 28 per cent of left ventricular surface area), transmural, usually first infarcts, produced by complete occlusion of a coronary artery, and had little opportunity to receive collateral blood flow because of either significant obstructions of adjacent arteries or the pattern of coronary artery distribution. Six hearts had inferior-basilar defects in inferior-septal infarcts and four had mid-apical defects in anterior-septal infarcts. Development of septal rupture may relate to alterations of septal configuration: more curved than normal with inferior-basilar ruptures and bulging into the outflow tract with mid-apical ruptures. Pain was a common feature (50 per cent) of the development of the septal defect. A loud holosystolic murmur and severe hypotension were noted in all cases. Left-sided congestive heart failure was absent in the early post-rupture period. Diagnosis was established by right heart catheterization in the eight patients studied. Post-rupture survival without operation varied from 0.5 to 52 days (average 8 days) and the interval from infarct to rupture ranged from 0.5 to 7 days (average 4 days). The clinical course and pathologic findings in these patients support the desirability of early operative intervention in septal ruptures complicating infarcts. © 1979.