Modification of the electrocardiogram of myocardial infarction by anomalous atrioventricular excitation (Wolff-Parkinson-White syndrome): Report of a case

Abstract

The difficulty in occasional instances of differentiating myocardial infarction from anomalous atrioventricular excitation (Wolff-Parkinson-White syndrome) has been noted by Levine and Beeson, 1 Palatucci and Knighton, 2 Eichert, 3 and Missal, Wood, and Leo. 4 The paroxysmal tachycardia which occurs so regularly with anomalous excitation may produce chest discomfort which may be mistaken for the pain of infarction, and the electrocardiogram of anomalous excitation may also cause confusion. Fischer, 5 Zoll and Sachs, 23 Goldbloom and Dumanis, 6 and Rinzler and Travell 24 have reported cases of the coexistence of the two conditions. In these cases electrocardiograms were not recorded during periods when the anomalous excitation reverted to normal excitation, so that there is no comparison between the two, and the effect of anomalous excitation on the electrocardiogram of myocardial infarction cannot be determined. In the case which is the basis of the present discussion there is definite evidence of the coexistence of the two conditions, and electrocardiograms were recorded shortly after infarction showing both normal and anomalous excitation. These electrocardiograms reveal the fact that anomalous atrioventricular excitation may obscure some of the diagnostic electrocardiographic signs of infarction, in this case, the Q wave. During normal excitation the electrocardiograms showed the characteristic Q 2 and Q 3 of posterior wall infarction. At other times, however, during anomalous excitation the Q 2 and Q 3 were absent, and the initial portions of QRS 2 and QRS 3 were small R waves.