Purpose: To determine the efficacy and identify the relevant factors for durable lesion creation in pulmonary vein isolation (PVI) using a high-power short-duration (HPSD) strategy.
Methods: Thirty-two consecutive patients who underwent PVI using HPSD (50 W) (HP group: HP-G) were compared with 32 controls using normal power (25-40 W) (conventional group: C-G). The segments were divided into 12 segments per group; thus, there were 768 segments for analysis. Radiofrequency (RF) ablation (RFA) was mainly performed under guidance with a unipolar electrogram at the distal tip of the ablation catheter in both groups. The high-power strategy reduced radiofrequency energy (P < 0.0001), RFA time (P < 0.0001), acute pulmonary vein reconnection (PVR) segments (P = 0.02), and several three-dimensional-mapping-related indices except for minimum impedance drop (Imp-min).
Results: There was a significant difference only in Imp-min between the subjects with acute PVR and those without in the HP-G (P = 0.002). Multivariate analysis revealed Imp-min to be the only independent predictor of the absence of PVR after adjusting for maximum inter-lesion distance and minimum ablation index (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.07-1.39, P = 0.001). In the region-specific analysis, this was attenuated in posterior segments, where the HP strategy independently predicted the absence of PVR (OR 2.80 [95% CI 1.32-6.30], P = 0.007).
Conclusion: The HPSD strategy reduced RF time, RF energy, and three-dimensional mapping-related indices but also improved the acute outcome. The HP strategy may be a sophisticated strategy under guidance with the impedance drop rather than the ablation index.
Keywords: Atrial fibrillation; Catheter ablation; High-power short-duration strategy; Impedance drop; Pulmonary vein isolation.