Prevalence of non-Q-wave acute myocardial infarction with total angiographic occlusion of the left circumflex coronary artery within eight weeks of infarction

Abstract

The genesis of Q waves in acute myocardial infarction (AMI) has been associated with complete occlusion of the infarct-related coronary artery by coronary arteriography and autopsy studies. 1 In contrast, subtotal coronary stenosis is described in association with non-Q-wave AMI. 2 Mapping studies of depolarization sequences in the isolated human heart show late activation of the lateral and posterobasal walls (≤70 ms after the earliest ventricular sites of excitation). 3 Transmural AMI involving these regions may result in no Q-wave genesis owing to this late activation sequence. Earlier studies that relate Q waves to transmural lateral AMI involved necropsy data. These studies are more likely biased toward large infarctions than clinical studies in living patients. This report evaluates the incidence of Q-wave AMI in patients with acute complete occlusion of the left circumflex coronary artery.