Relationship between Body Surface Isopotential Map of Myocardial Infarction and Coronary Angiographic Findings

Abstract

As a noninvasive method to determine the location and the extant of myocardial infarction, a body surface isopotential map is expected to have some advantages over a conventional electrocardiogram (ECG) or a vectorcardiogram, because of its greater number of leads points. We examined 15 cases with myocardial infarction by the body surface isopotential map, and the results were analyzed in correlation with ECG and the coronary angiographic findings (CAG). Material and Methods : The clinical material consisted of 15 patients with old myocardial infarction. The diagnosis was based upon clinical hictories, physical and laboratory findings, and abnormal Q waves in ECG. The abnormal Q and QS patterns were classified according to the criteria of AHA committee report. All cases had significant (90% decrease in diameter) obstructions in one of the major coronary arterise. In 10 cases, the obstructions were located in the anterior decsending branch of the left coronary artery (LAD), and in the remaining 5 cases, the obstructive lesions were in the right coronary arteries (RCA). Body surface isopotential maps (MAP) were constructed of unipolar lead ECG recordings from 85 lead points over the chest surface. Data were computer-processed and the potentials were plotted as sopotential maps at 1.5 msec intervals the QRS deflection. Results : The cases with LAD obstructions were classified into following three groups according to their sites of obstructions in LAD; group A whose obstructions were located in the proximal portion of LAD, group B whose obstructive sites were in the middle portion of LAD and group C in which obstructions were in the apical portion of LAD. Each group had its own characteristic map pattern. Five cases with RCA obstructions also showed a characteristic pattern.