Ventricular Activation in the Pre-Excitation Syndrome (Wolff-Parkinson-White)

Abstract
Seventy cases of pre-excitation were studied by vector translating methods. Certain properties of the delta event are described that are useful in the recognition of this syndrome electrocardiographically. In about half the cases a ventricular conduction defect without QRS-interval prolongation was demonstrated to have accompanied the pre-excitation. The type of ventricular conduction defect produced depended upon the particular direction of spread of the pre-excitation wave. This and other findings are incompatible with the hypothesis that pre-excitation is due to accelerated atrioventricular conduction and favor the hypothesis that it is due to bridges, whether morphologic or electronic, between atria and ventricles.