Wolff-Parkinson-White Syndrome: current concepts regarding its probable mechanism and report of a case with attacks of supraventricular pyroxymal tachycardia

ABSTRACT

The most accepted and, apparently, the most logical explanation for the W-P-W syndrome is the anomalous A-V conduction theory. But, while there is general agreement on the fundamental concept of an accessory pathway, there is much diasagreement regarding the details of the mechanism. Among the questions still unsettled are the nature, number and loation of this anomalous bundle; whether the A-V conducting system is functioning or not; and what the course and fate of the shortcircuited impulse is after reaching the ventricles2) In view of the conflicting and apparently irreconcilable differences among the various workers, we venture the conclusion that these differences probably need not be reconciled because the pathology present may not be exactly the same in the different patients studied. The anomalous bundle being an anomalous structure, by its very nature, should be variable. Hence, it may be single or multiple, unilateral or bilateral, it may end near or at a distance from the septum and A-V conducting system, and it may, therefore, either supplement the later or replace it altogether3) A rare case of W-P-W syndrome in a Filipino is presented. This patient came with presenting signs and symptoms of paroxysmal tachycardia of auricular origin4) The anomalous pathway in this patient was localized electrocardiographically at the left posterior position, conducting impulses in an epicardial-to-endocardial direction5) Electrocardiographyically, the paroxysmal tachycardia closely simulated paroxysmal ventricular tachycardia. The differentiation between supraventricular and ventricular tachycardia is discussed. The probable mechanism causing the attacks of tachycardia are evaluated6) The predisposition of W-P-W patients to attacks of paroxysmal tachycardia should be borne in mind, for it can serve as an aid both in the prognostification of the arrhythmia, as well as in the diagnosis of W-P-W syndrome. The possibility of W-P-W syndrome should be entertained in patients with histories of repeated attacks of tachycardia. (Summary and Conclusion)