Ecg in Strictly Posterior Myocardial Infarction

ECGs from 215 patients with a diagnosis of recent myocardial infarction and a case history shorter than 48 hours have been examined. Sixty‐eight had “anterior” myocardial infarctions (group 1). Seventy‐seven had “posterior” myocardial infarctions (group 2). Seventy had equivocal ECG signs of recent myocardial infarction (group 3). In group 3 thirteen patients had R/S quotients >1 in V 1 and/or V 2 . In group 2 sixteen patients had R/S quotients > 1 in V 1 and/or V 2 together with the ordinary “posterior myocardial infarction” pattern. In the absence of right bundle branch block, WPW syndrome, congenital heart disease, chronic advanced pulmonary disease or any other diseases which cause pure right ventricular hypertrophy, this sign points to a myocardial infarction in the strictly posterior (or posterolateral) aspects of the left ventricle. The electrophysiological basis of this finding is discussed briefly. It is stressed that this ECG sign is not rare as it was the sole ECG sign of recent myocardial infarction in 6% of patients in this study. In another 8% it was seen together with the ordinary Q 2–3‐a VF pattern of “posterior” (diaphragmatic) myocardial infarction.