Coexistence of the Wolff-Parkinson-White preexcitation syndrome and complete atrioventricular block.

This report documents a young male with Wolff-Parkinson-White preexcitation syndrome who developed the rare occurrence of type 11 second degree Kent bundle block, and subsequently complete accessory pathway block simultaneously with complete suprahisian atrioventricular block. Also, there appears to be a mild degree of right bundle branch block associated to the preexcitation pattern. Additionally, automaticity in an accessory pathway, very rare, is suggested, but yet unproven. The Wolff-Parkinson-White (WPW) preexcitation (PE) syndrome coexisting with atrioventricular (AV) block is rare (1-3). The AV conduction disturbance may exist in the AV nodal His-Purkinje conduction pathway or in the accessory pathway (AP), or in both the AV conduction system and in a bypass tract simultaneously. The conduction disturbances may be intermittent, or fixed and permanent (1-15). Even more rare is the existence of automaticity in an accessory pathway (3, 5, 16-27). The WPW syndrome has been infrequently reported associated with a bundle branch block (BBB) (28-30). This report documents a patient with the WPW PE pattern who developed type II second degree Kent bundle AP blocks, and subsequently complete AP blocks, perhaps in two APs, simultaneously with complete suprahisian AV block in the normal conduction system. Additionally, automatic ectopic impulse formation is possible in an accessory pathway. Moreover, there is a suggestion of a mild bundle branch block pattern associated with the ventricular preexcitation.