Extension of catheter ablation and outcome for ventricular tachycardia or premature ventricular contractions from the right ventricular outflow tract

Objective We aimed to determine whether the extension of ablation could influence the ablation outcome for ventricular tachycardia (VT)/premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). Methods and results The radiofrequency catheter ablation results of 33 VT/6 frequent PVCs from the RVOT were analysed. The ablation extension was divided into 3 categories from the final successful ablation point with the earliest activation: (I) focal ablation (15 cases); ablation at 1 or 2 points; (II) focal with extended ablation (12 cases); focal and surrounding area ablation (maximum ≤1 cm) after elimination of clinical VT/PVCs; and (III) broad ablation (12 cases); continued broad ablation (maximum >1 cm) after elimination of clinical VT/PVCs. Acute termination was defined as the complete elimination and non-inducibility of clinical VT/PVCs during the procedure. For the mean follow-up of 12.8 months, the recurrence rate was not significantly different among the groups (P = 0.49). The mean procedure time was longer in group II, but ablation times and complication rates were not different among the groups. When acute termination was achieved, the overall recurrence rate was 7.6%. However, when confirming absence of the clinical VT/PVCs using 24-hour Holter monitoring immediately after the procedure, the recurrence rate was 2.7%. Conclusions Ablation extension did not affect ablation outcome of VT/PVCs from the RVOT. Confirmation of absence of clinical VT/PVCs using 24-hour Holter monitoring immediately after the procedure could guarantee long-term success.