TRANSCATHETER RADIOFREQUENCY ABLATION - EARLY EXPERIENCE WITH SUPRAVENTRICULAR TACHYARRHYTHMIAS RELATED TO ACCESSORY ATRIOVENTRICULAR AND DUAL ATRIOVENTRICULAR NODAL PATHWAYS

Objective: To describe our initial experience with transcatheter radio frequency ablation, a useful new treatment for supraventricular tachya rrhythmias related to the presence of an accessory atrioventricular (A V) pathway or dual atrioventricular nodal pathways. Patients and metho ds: One hundred and ten patients, including 77 with accessory pathways , 32 with dual atrioventricular (AV) nodal pathways and one with both, underwent electrophysiological studies and were treated with transcat heter radiofrequency ablation in a large metropolitan teaching hospita l. Results: Ninety-five patients (86%) were without evidence of access ory pathway conduction or inducible supraventricular tachycardia and w ere free of symptoms after a mean follow-up of 13 months (range, 3.0-5 1 months). Sixty-six of 79 accessory pathways (83.5%) were ablated inc luding 42 of 46 left-sided (91%),14 of 21 posteroseptal (66%), six of seven anteroseptal (86%), three of four right-sided and one of one mid septal pathways. Thirty-one patients with AV nodal reentry were succes sfully treated by ablation of either the slow (12 patients) or fast (1 9 patients) conducting AV nodal pathway. There was a progressive impro vement in the success rate of the first procedure from 17% to 64% with the use of large-tip catheters and from 64% to 91 % when a purpose-bu ilt radiofrequency generator was employed. Complications occurred in n ine patients: cardiac tamponade (two patients); mild mitral regurgitat ion (four); subclavian vein thrombosis (one); transient cerebral ischa emic attack (one); and non-thrombocytic purpuric rash (one). These occ urred predominantly during the early experience and were without long- term sequelae. Late in our experience, one patient developed complete atrioventricular block requiring permanent pacemaker implantation. Con clusions: In this institution, radiofrequency catheter ablation has be en a safe and effective treatment strategy for patients with life-thre atening or highly symptomatic supraventricular arrhythmias.