Catheter ablation of the atrioventricular conduction system in patients with supraventricular tachycardia.

In rare circumstances, patients with disabling supraventricular tachycardia that proves refractory to treatment with medication or antitachycardia pacing devices may require interruption of normal atrioventricular conduction and implantation of a permanent pacemaker for effective control of their arrhythmia. In the past, a cardiac surgical procedure was required to interrupt normal atrioventricular conduction; however, a closed-chest catheter technique to interrupt normal atrioventricular conduction has recently been described. We describe three patients in whom normal atrioventricular conduction was interrupted with this closed-chest technique. The procedure was accomplished without complication in all patients after invasive electrophysiologic studies were used to evaluate the mechanisms of tachycardia, the characteristics of the atrioventricular conduction system, and the potential use of antitachycardia pacing systems. All patients remain alive 5 to 9 months after the procedure, with no signs of recovery of normal atrioventricular conduction and no evidence of pacemaker dysfunction. Catheter ablation of the atrioventricular conduction system offers a promising alternative to a cardiac surgical procedure in carefully selected patients with disabling supraventricular tachycardia.