Outcome of myocardial infarctions complicated by heart conduction disorders in the acute phase

: Of 945 patients hospitalised for myocardial infarction between January 1st 1972 and December 31st 1975, 40 with anterior myocardial infarction (Group I-A) and 53 with posterior myocardial infarction (Group II-A) were complicated by atrioventricular and/or intraventricular arrhythmias. The average follow up period is now of 48 months (range 24 to 78 months). Their outcome was compared to two control groups of 50 anterior myocardial infarctions (Group I-B) and 50 posterior myocardial infarctions (Group II-B) uncomplicated by arrhythmias in the acute phase. The immediate (10%) and secondary (30%) mortality was identical in the two groups II-A and II-B with posterior wall necrosis. The immediate (32%) and secondary (40%) mortality in Group I-A was much higher than in Group I-B (22% and 28% respectively). Sudden death was the most frequent form of demise in all groups (I-A, II-A, II-B) except Group I-B in which heart failure predominated. Death occured earlier in Group I-A than in the control Group II-B. These results pose the problem of the indication of prophylactic permanent pacing to decrease the incidence of sudden death.