Contact Index–Guided Pulsed Field Ablation: A Two‐Phase Validation of the Impedance Change Threshold to Prevent Acute Pulmonary Vein Gaps

Background: Pulsed field ablation (PFA) for atrial fibrillation (AF) requires adequate catheter-tissue contact. The Contact Index visualizes impedance change for the pentaspline catheter, but a validated contact threshold is unknown. Objective: The objective of this study is to define an impedance-change cutoff that predicts sufficient contact to prevent acute pulmonary vein gaps (PVG) during pulmonary vein isolation (PVI), and to validate Contact-Index-guided PVI. Methods: = 26) delivered energy only when all target splines met/exceeded the cutoff value obtained from Phase 1. Results: < 0.001) compared with Phase 1. Procedure time, PVI time, fluoroscopy time, and total applications were similar between phases. Conclusions: An impedance-change threshold of ≥ 10% on the Contact Index reliably indicates adequate contact with the pentaspline catheter and, when enforced, reduces acute PVG without prolonging procedures.