CASE REPORTS Reentry Within the Atrioventricular Node: Surgical Cure with Preservation of Atrioventricular Conduction

SUMMARY Paroxysmal supraventricular tachycardia (PSVT) is commonly caused by reentry within the atrioventricular (AV) node. This arrhythmia was abolished by operative dissection of the AV junction in a patient with disabling tachycardia that was not controlled by drugs. The operation was intended to create com-plete AV block, but AV conduction persisted after surgery. An electrophysiologic study 1 year after the opera-tion revealed that the operation changed AV conduction in both the antegrade and retrograde directions, which may explain the absence of tachycardia. The patient has been free of arrhythmias for 18 months. PAROXYSMAL SUPRAVENTRICULAR tachy-cardia (PSVT) caused by reentry using an accessory atrioventricular (AV) pathway has been successfully treated with surgical division of the accessory pathway when drug therapy has failed. ' This operation is per-formed without damaging the normal AV conduction system. In contrast, some patients who have PSVT caused by reentry within the AV node have been treated with destruction of the normal AV conductio