Serial Electrocardiograms After Myocardial Infarction

Abstract

There were no significant effects of long term estrogen therapy on serial electrocardiograms of middle aged males who had suffered a myocardial infarction. Of those patients surviving the first 8 weeks, 6% with acute transmural myocardial infarctions, in contrast to 34% with non-transmural infarctions, had normal electrocardiograms within 3 1/2 years. Thus the presence of a normal electrocardiogram represents strong, but not conclusive, evidence against a remote clinical transmural myocardial infarction. The same cannot be said for non-transmural infarctions. Long term prognosis is not significantly better in non-transmural than transmural infarctions, despite the more frequent return to normalcy of the electrocardiograms in the former group. Within 1 1/2 years post infarction the Q waves of transmural infarcts will either disappear or become of borderline significance in 30% of the cases. This indicates a sizeable chance for error in tabulating remote transmural myocardial infarctions solely on the basis of recent electrocardiograms. Long term prognosis is not affected by the electrocardiographic location of the infarction, by the infarction being either transmural or non-transmural, or by the disappearance of Q waves in the electrocardiogram of transmural infarctions. Serial electrocardiography alone is not a useful tool for predicting long term survival after acute myocardial infarction.