Role of residual potentials inside circumferential pulmonary veins ablation lines in the recurrence of paroxysmal atrial fibrillation.

BACKGROUND: Residual gaps due to incomplete ablation lines are known to be the most common cause of recurrent atrial fibrillation (AF) after catheter ablation. We hypothesized that any residual potentials at the junction of the left atrium and pulmonary vein (PV), inside the circumferential PV ablation (CPVA) lines, would contribute to the recurrence of AF or post-AF ablation atrial flutter (AFL); therefore, the elimination of these potentials increases AF-/AFL-free survival rates.

METHODS AND RESULTS: One hundred and two patients with paroxysmal AF (PAF) were enrolled and prospectively randomized to a group with ablation of residual potentials as add-on therapy to CPVA + PV electrical isolation (PVI) (group 1, n = 49), or a group without ablation of the residual potentials (group 2, n = 53). Post-CPVA residual potentials, inside the ablation lines, were identified by contact bipolar electrode mapping catheter and a detailed 3-dimensional voltage map. Twenty-three patients in group 1 and 18 patients in group 2 had post-CPVA residual potentials (46.9% vs 34.0%, P = 0.182). The AF-/AFL-free survival rate during follow-up of 23.3 ± 7.9 months was not different in comparisons between the 2 groups (P = 0.818), and 79.6% and 81.1% of the patients in groups 1 and 2 maintained a sinus rhythm (P = 0.845), respectively.

CONCLUSIONS: Residual potentials inside CPVA were commonly found in the patients with PAF after CPVA + PVI. Further ablation of residual potentials did not increase the efficacy of catheter ablation in patients with PAF.