[Contribution of His bundle electrocardiography for the study of Wolff-Parkinson-White syndrome]

In this work particular emphasis is paid to the contribution of His bundle recordings associated with atrial pacing to the understanding of the Wolff-Parkinson-White syndrome. The methodology used for the electrophysiological studies is described in detail. The value of this particular type of recordings in WPW is demonstrated by the analysis of some illustrative cases which led us to a better knowledge of the electrocardiographic changes, and to the separation of several patterns of ventricular preexcitation and their relationship to the different anatomical pathways postulated for this syndrome. In some instances it was possible to caractherize the reentry circuit of reciprocating paroxysmal tachycardias and to estimate the refractory periods of the normal and the accessory pathways. These later data may be of value for a more rational therapeutic approach of the paroxysmal arrhythmias in the WPW syndrome.