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Background: Optimal overlap ratio remains unclear in point-by-point laser balloon (LB) ablation. Objective: This study sought to determine the optimal overlap strategy with target energies on the acute and chronic outcomes in LB pulmonary vein (PV) isolation (PVI). Methods: Consecutive 38 patients (148 PVs) with atrial fibrillation underwent the first-generation LB PVI with the following protocols based on the overlap ratios for each PV anterior/posterior wall: 50%/50% (13 patients [49 PVs], group A), 50%/25% (15 patients [60 PVs], group B), and 25%/25% (10 patients [39 PVs], group C). High energies (240–255 J: 12 W / 20 seconds, 8.5 W / 30 seconds), moderate energies (200–210 J: 10 W / 20 seconds, 7 W / 30 seconds), and low-to-moderate energies (low, 165–170 J: 5.5 W / 30 seconds, 8.5 W / 20 seconds) were targeted for left PV anterior walls, right PV anterior walls, and bilateral PV posterior walls, respectively. First-pass PVI, the other procedure-related data, and atrial tachyarrhythmia recurrences were analyzed. Results: First-pass PVI rate per PV was higher in group A (94%) than in group B (88%) and group C (62%) (P < .001). All PVs were finally isolated. First-pass time, total LB PVI time, complications, and atrial tachyarrhythmia recurrences during a mean follow-up of 11 ± 5 months did not differ between the groups. A few residual gaps after first-pass LB ablations were found for PV anterior walls even in group A and group B. Conclusion: Sufficiently overlapped LB ablation promises a high rate of first-pass PVI without adverse outcomes. High energy could be required for PV anterior walls.

Background: A surface temperature sensor can be used to visualize the effect of hot balloon (HB) catheters. This study evaluated the efficacy and safety of a second-generation HB system with surface temperature monitoring in patients with atrial fibrillation (AF). Methods: Twenty patients (age: 69.6 ± 9.7 years, 11 male participants) who underwent first-time pulmonary vein isolation (PVI) using a second-generation HB were included. For each pulmonary vein (PV), the acute isolation rate and effective therapeutic range of surface temperature were investigated. Results: Eighty-three PVs (including three right middle PVs) were isolated in 20 patients using an HB with a surface temperature sensor. Sixty-eight PVs were isolated using the first application. Fifteen PVs (left superior PV [LSPV], n = 7 [35%]; left inferior PV, n = 2 [10%]; right superior PV, n = 3 [15%]; right inferior PV, n = 3 [15%]) showed early intraoperative reconduction and required second applications. One LSPV required radiofrequency touch-up at the carina. The optimal balloon surface temperature and application time were evaluated, and a median value of 58 °C and integral value of 1000 °C·s were identified from the receiver operating characteristic curve to be useful effective indicators. However, for LSPV, the PV potential of carina or ridge likely often remained and needed to be independently considered. There was no periprocedural complication including severe pulmonary vein stenosis. During the observation period (median: 280 days, interquartile range: 261–318 days), 17 patients (85%) achieved and maintained sinus rhythm. Conclusions: Second-generation HBs with a surface temperature sensor are expected to provide favorable outcomes in AF ablation treatment.