LONG-TERM RESULTS OF CATHETER ABLATION FOR IDIOPATHIC VENTRICULAR-TACHYCARDIA ORIGINATED FROM THE RIGHT-VENTRICULAR OUTFLOW

We performed catheter ablation in 10 consecutive patients with idiopat hic monomorphic right ventricular tachycardia and studied the long-ter m outcome. All ventricular tachycardias had a left bundle branch block configuration with an inferior axis, and originated from right ventri cular outflow. Antiarrhythmic drugs (3-6 drugs) had been ineffective i n controlling ventricular tachycardia. The 2 patients who underwent di rect-current ablation (2 shocks of 150 J) had no recurrence of ventric ular tachycardia and did not require antiarrhythmic drugs during a fol low-up of 56 and 51 months, respectively. Of the 8 patients who underw ent radiofrequency ablation (30-40 watt, 20-40 sec, 2 - 15 application , using Inter Nova RA 50, 13.56 MHz), 1 patient had no rccurrence of v entricular tachycardias and did not require antiarrhythmic drugs, 4 pa tients had no recurrence of ventricular tachycardias but did require a ntiarrhythmic drugs, and 3 patients experienced recurrence of non-sust ained ventricular tachycardia despite the use of antiarrhythmic drugs during a follow-up of 15 40 months. There were no complications except for cardiac perforation which occurred immediately after direct-curre nt ablation in 1 patient. In conclusion, long-term success in preventi ng ventricular tachycardia was achievable with direct-current ablation , but this success was associated with serious risks, such as cardiac perforation. Radiofrequency ablation was safer than direct-current abl ation, but had a lower long-term success rate.