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

Abstract

Abstract 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.