QS and QR pattern in leads V₃ and V₄ : Electrocardiographic and Pathologic Correlation on 41 Cases, Including 25 Cases without Myocardial Infarction

Abstract

Although a QS or QR pattern in leads V₃ and V₄ is generally accepted as a diagnostic sign of myocardial infarction, similar patterns are also found in cases without infarction. Among 41 autopsied cases with significant Q waves in leads V₃ and V₄ there were 25 not associated with myocardial infarction. These electrocardiographic abnormalities were rather frequently observed at terminal stage and also in cases with severe pulmonary emphysema. It is difficult to decide whether myocardial infarction is present when significant Q waves persist without any other definite signs and symptoms, although the presence of coronary T wave in a precordial lead and/or marked left axis deviation is suggestive of infarction. The cause of significant Q waves in the absence of myocardial infarction was discussed and altered position of the heart was suggested to be responsible.