Clinical Role of Catheter Ablation of Atrioventricular Junction

Abstract

In the 94 years since the discovery of the atrioventricular (AV) conduction system, many therapeutic modalities have been developed to alter or abolish AV conduction in order to treat patients with symptomatic supraventricular tachyarrhythmias (SVT). The mainstay of therapy has been, and remains, pharmacologic agents. For a very select subgroup of patients with disabling or life-threatening SVT who are refractory to either conventional or experimental drug therapy, alternative techniques involving antitachycardia pacemakers and both open-and closed-chest surgical and catheter approaches have been developed. Preliminary animal studies to interrupt AV conduction involved direct mechanical crushing [1,2], surgical incision [3, 4], cautery, [4], ligation of septal arteries [5], injection of caustic material [6–8], cryosurgical ablation [9], and electrode catheter ablation [10]. The earliest cases of therapeutic production of third-degree AV block in man involved direct incision of the AV junction or ligature of the AV node [11, 12]. Later techniques involved open-chest procedures utilizing needle electrocoagulation [13], excision of the AV node [14], and what ultimately has proven to be the surgical procedure of choice, cryoablation of the AV junction [9].