Development and Validation of a Novel Contact Force-Integrated Pulsed Field Quantization Index for Pulmonary Vein...

There is no bipolar-specific quantitative ablation index currently available to guide pulsed field ablation (PFA). We aimed to develop and validate a novel contact force (CF)-integrated pulsed field quantization index (PFQI) for real-time lesion depth prediction during bipolar PFA.

In total, 27 healthy Yorkshire swine were included in a two-phase preclinical study. In Phase I, a nonlinear multivariable model was developed to derive a novel PFQI incorporating real-time CF, pulse train number, delivery voltage, and impedance variation. In Phase II, the PFQI was prospectively validated by comparing predicted with actual lesion depth, followed by PFQI-guided circumferential pulmonary vein isolation (PVI). Acute procedural success, 30-day PVI durability, and extracardiac safety were evaluated using serial electroanatomic mapping and blinded histopathological examination. Lesion depth was strongly associated with CF, pulse train number, voltage, and impedance change. The PFQI predicted actual depth with high accuracy (R = 0.94, R² = 0.88; validation R² = 0.82, slope = 1.014). In the validation cohort, 92% of predicted depths fell within ±0.75 mm of measured values. PFQI-guided PVI achieved 100% (6/6) acute isolation and 100% 30-day durable electrical isolation, with contiguous transmural fibrosis on histology. No collateral phrenic nerve, esophageal, or pulmonary vein injury occurred, and phrenic capture thresholds remained unchanged.

The PFQI is the first bipolar-specific, CF-integrated quantitative metric for PFA, enabling accurate, real-time lesion depth prediction. PFQI-guided PVI achieved consistent, durable, and safe PVI in a porcine model, providing a promising operator-independent quantitative strategy to optimize clinical bipolar PFA for atrial fibrillation.