Q-wave infarction: Pathophysiology of body surface potential map and ventriculographic patterns in anterior and inferior groups

To define and relate the body surface electrocardiographic and left ventricular wall motion patterns in the acute phase of Q-wave infarction, we recorded 120-lead body surface potential maps and radionuclear angiograms in 29 patients on the fifth day of their first infarction. By standard 12-lead electrocardiographic criteria, 17 patients were designated as anterior infarction and 12 as inferior infarction. Body surface map infarct patterns in the anterior group were characterized primarily by abnormal Q-wave, negative Q-zone and positive ST-segment integral patterns over the anterior torso and little reciprocal change. The maps of the inferior patient group were characterized primarily by depolarization and repolarization infarct patterns over the inferior torso and marked reciprocal changes in all integral patterns over the anterior torso. Both groups displayed infarct patterns over a common area of the right anterior-inferior torso. In the anterior group depolorization minima and repolarization maxima were clustered in a small precordial area; in the inferior group the same extrema were widely scattered over the inferior torso, both anteriorly and posteriorly. Segmental left ventricular wall motion analysis revealed that the 3 most commonly and most severely involved segments were the same in both infarct groups - apical, infero-apical and antero-lateral. Basal septum and antero-basal segmental dysfunction were exclusive to the anterior group; postero-lateral and infero-basal involvement, to the inferior group. Multivariate analysis (Q-zone minimum; Σ Q-wave; ST maximum, ejection fraction; and, wall motion abnormality score) revealed the groups to be markedly (p < 0.001) different with the mean values of all variables of the multivariate set significantly (p < 0.001 to p < 0.05) more abnormal for the anterior, as compared to the inferior, group. Thus, despite some spatial similarities of electrocardiographic and ventriculographic infarct patterns, the results of this study support the clinical differentiation of Q-wave infarction patients into anterior and inferior groups. Most importantly, the data suggest that patients with anterior infarction have greater acute-phase myocardial injury than inferior infarction patients.