Effect of ablation at high‐dominant frequency sites overlapping with low‐voltage areas after pulmonary vein isolation of nonparoxysmal atrial fibrillation

Abstract

Background The relationship between high‐dominant frequency (DF) sites and low‐voltage areas (LVAs) in nonparoxysmal atrial fibrillation (AF) patients still remains unknown. Objective This study aimed to evaluate the effect of ablation at high‐DF sites overlapping with LVAs after pulmonary vein ablation (PVI) of nonparoxysmal AF. Methods A total of 128 consecutive nonparoxysmal patients with atrial fibrillation (53 persistent AF) were retrospectively investigated. The patients with AF were divided into two groups: patients with circumferential PVI alone (PVI group, n = 57) and those with PVI followed by a DF‐based ablation (DF group, n = 71). Results The patient characteristics did not significantly differ between the two groups. However, the LVA ( < 0.5 mV)/left atrial (LA) surface was significantly greater in the DF than the PVI group (22% vs 16%, P = .02). The total max‐DF sites overlapping with LVAs in the LA were significantly greater in the DF than the PVI group (91% vs 10%, P = .001). The atrial arrhythmia freedom on antiarrhythmic drugs in the DF group was significantly greater than that in the PVI group during 10.0 ± 3.2 months of follow‐up (83.1% vs 64.9%, log‐rank test P = .021). The event‐free survival in the PVI group decreased according to the LVA extent while it was > 80% in the DF group. The event‐free survival in patients with AF especially with extensive LVAs ( ≥ 30%) in the DF group was significantly greater than that in the PVI group (81.0% vs 45.5%, log‐rank test P = .035). Conclusions High‐DF sites overlapping with LVAs after the PVI may be potential selective targets for modification of atrial substrates in nonparoxysmal AF patients.

Predictors of recurrence of atrial tachyarrhythmias after pulmonary vein isolation by functional and structural mapping of nonparoxysmal atrial fibrillation

“…The catheter ablation procedure was performed using a NavX system (St. Jude Medical) as described previously 12,14,16 . A 5‐french deflectable catheter was inserted into the coronary sinus (CS) via the right femoral vein.…”

“…The 3D LA geometry was created using a 7‐F decapolar circular catheter (EPstar Libero, Japan Lifeline Co., Ltd.). The whole LA was divided into eight areas (PVs, roof, left atrial appendage [LAA], septum, and lateral, anterior, inferior, and posterior regions) for a location analysis of the LVAs, DFs, and rotors 12,14,16 . The mapping points in each region were similar in number and nearly equally distributed (LA mean mapping points: 1843 ± 501).…”

“…The PVI was performed guided by a 7‐F decapolar circular catheter positioned at the PV ostia as described previously 12,14,16 . Each radiofrequency (RF) energy application was delivered for 40s.…”

“…After the PVI, DF mapping during AF in each area was performed using the fast Fourier transform (FFT) method described previously 12,14,16 . Recordings at each site for 5 s were performed using a deflectable 20‐pole spiral‐shaped catheter with a diameter of 2.5 cm (Reflexion HDTM, St. Jude Medical).…”

“…Furthermore, functional mapping as automatic detection of high‐DF sites and rotational activations by a novel phase mapping system may potentially selectively target localized sources maintaining AF in nonparoxysmal AF patients 9–13 . We previously reported the importance of high‐DF sites overlapping with LVAs that are present using a conventional mapping catheter after the PVI 14 . However, the predictors of recurrence of atrial tachyarrhythmias detected after the PVI by both structural and functional mapping of nonparoxysmal AF remain unclear.…”