Studies of male survivors of myocardial infarction. VI. The electrocardiogram.

Electrocardiograms of 101 men who survived myocardial infarction for at least three months and were free of hypertension, heart failure and other significant disease were analyzed. Within the range of 30 to 70 years, age had no apparent influence on the ECG. Six ECGs were borderline, 79 were abnormal and 16 had returned to normal. Of those with the pattern of infarction, 56 were transmural and 22 nontransmural. For all cases, posterior involvement was somewhat more common than anterior (46 to 32), but it was less common in non-transmural infarction. Ventricular premature beats, always unifocal and few in number, were the only abnormality in rhythm. Atrial fibrillation was conspicuously absent. There were four instances of complete left bundle-branch block. No evidence of left ventricular hypertrophy was seen. The clinical significance of these observations is briefly discussed.