Cardiac potentials on body surface of infants with anomalous left coronary artery (myocardial infarction).

The body surface potential distribution in two infants with myocardial infarction secondary to anomalous origin of the left coronary from the pulmonary artery demonstrated: (1) the persistence of a minimum in the area overlying the infarct during inscription of the prominent Q wave in V6, and, (2) the presence of a terminal maximum in an adjacent area overlying the infarct. The terminal maximum was considered to represent peri-infarction "block" resulting from persistence of wave fronts in the ischemic muscle surrounding the infarct as suggested by the studies of Durrer and associates. Postoperatively, there was persistence of the initial minima overlying the area of the infarct. Finally, there was disappearance or marked diminution in the terminal maximum overlying the area of the infarct following surgical enhancement of myocardial blood supply.