Evaluation of laser balloon pulmonary vein isolation lesions during the acute and chronic phases using a high-resolution mapping system

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Visually guided laser balloon (VGLB) has proven ample efficacy in achieving durable pulmonary vein (PV) isolation (PVI). Though the isolation area post-cryoballoon ablation has been reported to regress at the chronic phase, the shrinkage of the isolation area using VGLB during the chronic phase has not been described. PURPOSE: This study aims to evaluate the differences in isolation areas created by VGLB between the acute and chronic phases using a high-resolution mapping system. METHODS: We assessed 26 patients who underwent a second procedure due to atrial fibrillation recurrence. Of them, 8 patients were treated with the third-generation VGLB and 18 patients were treated with the first-generation VGLB at the first session. In all patients, the voltage maps were created with high-resolution mapping catheters just after PVI (acute phase) and during the second session (chronic phase). With each map, the isolation area (<0.1mV) around the PV antrum was calculated. We validated the persistent durability of PVI, and then the regression of isolation lesions was analyzed in patients without any PV reconnections. RESULTS: The isolation areas were re-evaluated at 8.3±6.6 months after the initial procedure. Twenty patients (76.9%) preserved persistent isolation lesions of all four PVs. Of them, the reduction of the isolation areas on the left- and right-sided PV antrum were 1.6±3.2 cm² (10.7±23.1% of the acute phase) and 4.8±3.6 cm² (27.8±18.9%), respectively. The analysis of the results revealed that the isolation area of the right-sided PV antrum yielded statistical shrinkage during the chronic phase (P=0.001), even though the electrical isolation was preserved. CONCLUSION: After VGLB ablation, the isolation area of the right-sided PV antrum significantly regressed at the chronic phase, while the rate of durable PVI was high in line with the previous report. [Figure: see text]