To describe our initial experience with transcatheter radiofrequency ablation, a useful new treatment for supraventricular tachyarrhythmias related to the presence of an accessory atrioventricular (AV) pathway or dual atrioventricular nodal pathways.
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 transcatheter radiofrequency ablation in a large metropolitan teaching hospital.
Ninety-five patients (86%) were without evidence of accessory pathway conduction or inducible supraventricular tachycardia and were free of symptoms after a mean follow-up of 13 months (range, 3.0-51 months). Sixty-six of 79 accessory pathways (83.5%) were ablated including 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 midseptal pathways. Thirty-one patients with AV nodal reentry were successfully treated by ablation of either the slow (12 patients) or fast (19 patients) conducting AV nodal pathway. There was a progressive improvement 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-built radiofrequency generator was employed. Complications occurred in nine patients: cardiac tamponade (two patients); mild mitral regurgitation (four); subclavian vein thrombosis (one); transient cerebral ischaemic attack (one); and non-thrombocytic purpuric rash (one). These occurred 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.
In this institution, radiofrequency catheter ablation has been a safe and effective treatment strategy for patients with life-threatening or highly symptomatic supraventricular arrhythmias.