A retrospective analysis of 1,556 pulsed-field ablation (PFA) applications in 23 patients undergoing pulmonary vein isolation found that Bipolar Local Impedance Delta (BiLID) — measuring the per-application drop in bipolar local impedance — correlated strongly with peak creatine kinase-MB (r=0.71; 95% CI 0.42–0.87; P=0.0001), a biomarker of myocardial tissue injury. By contrast, neither total application count (r=0.16) nor TPI-positive signal count (r=0.26) reached statistical significance for predicting CK-MB elevation. BiLID also varied systematically by anatomical location, with lower coupling detected during right versus left pulmonary vein ablation.
PFA has rapidly displaced thermal radiofrequency ablation in electrophysiology labs due to its preferential cardiomyocyte selectivity and reduced esophageal injury risk. However, a persistent clinical blind spot has been the inability to quantify real-time energy delivery quality beyond binary contact flags. BiLID addresses this gap by providing a continuous, reproducible readout derived from standard mapping system displays — no proprietary data export required. The r=0.71 correlation with CK-MB is clinically meaningful, suggesting BiLID captures genuine tissue-energy coupling variation rather than noise. The finding that female sex, heart failure, and larger left atrial volume index associate with lower CK-MB elevation hints at important substrate heterogeneity that may demand individualized dosing strategies. Limitations are substantial: the cohort is small (23 patients), retrospective, and single-center. As a preprint not yet peer-reviewed, these findings require independent prospective validation before influencing procedural protocols. Nevertheless, this represents a potentially impactful methodological advance for precision-guided ablation titration.