Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Ablation Techniques D-PO02 - Poster Session II (ID 47) Poster

D-PO02-146 - Influence Of Overlap Ratio And Total Energy On The Residual Gap Formation After Initial Circular Laser Balloon Ablation (ID 1031)


Background: Residual gap of pulmonary vein (PV) after initial circular laser balloon (LB) ablation with point-by-point fashion derives from insufficient lesion size and continuity.
Objective: We aimed to evaluate the influence of strictly fixed overlap ratios and total energy (J) on residual gap formation after initial circular ablation using the first-generation LB.
Methods: A total of 27 patients (106 PVs) with paroxysmal atrial fibrillation underwent PV isolation using LB. All ablations were performed with the following three protocols of overlap ratio in each anterior/posterior wall of PV; 50%/50% (10 patients [38 PVs], group A), 50%/25% (12 patients [48 PVs], group B), and 25%/25% (5 patients [20 PVs], group C), respectively. In combination with fixed overlap ratio, total energy was classified into three ranges (high, ≥240 J: 8.5 W/30 seconds and 12 W/20 seconds; moderate, 200-210 J: 10 W/20 seconds and 7 W/30 seconds; low, 165-170 J: 8.5 W/20 seconds and 5.5 W/30 seconds). Low-to-high energy range and low-to-moderate energy range were selected in ablation for each PV anterior and posterior wall, respectively. Residual gaps after initial circular ablation were analyzed.
Results: In 14/27 (52%) patients (89/106 [84%] PVs), all PVs were isolated after initial circular ablation and total of 17 gaps were evaluated. There were 4, 2, 6, and 5 gaps in left PV anterior, left PV posterior, right PV anterior, and right PV posterior wall, respectively. One gap was detected per PV in all patients. The success rate of PV isolation after initial circular ablation was higher in group A (35/38 [92%] PVs) than in group B (41/48 [85%] PVs) and C (13/20 [65%] PVs) (p = 0.026). In group A, there was no gap in posterior wall of left and right PVs. However, one gap in right PV anterior wall after ablation with moderate energy range ablation and one gap in left PV anterior wall after ablation with high energy range were observed even in group A.
Conclusion: A sufficient overlap ratio of 50% improves the ratio of acute PV isolation after initial circular LB ablation, although moderate-to-high energy may be required for PV anterior wall in some cases even with 50% overlap ratio.