Myocardial infarction complicated by heart block--treatment and long-term prognosis.

A number of 597 patients with acute myocardial infarction (AMI) were treated with continuous ECG monitoring of the heart rhythm in a coronary care unit for at least three days. We found 84 patients with heart block, 39 with complete, 29 with at most second degree and 16 with at most first degree heart block. The treatment was primarily conservative; 22 of the 39 patients with complete heart block were given isoproterenol and two received temporary pacemakers. Survival was traced over two years in the whole patient group with myocardial infarctions. Heart block implied a worsened prognosis over the two years, but survival was independent of the degree of heart block. Among those with complete heart block, survival did not differ from that of a comparable patient series from Copenhagen, where all patients were given pacemakers. This does not support indiscriminate artificial pacing of patients with AMI and complete heart block. Our results ought to be controlled in a randomized study.