Automated measurement of epicardial unipolar local signal energy after pulsed field ablation in a preclinical model

Background Pulsed Field Ablation (PFA), a novel energy source based on irreversible electroporation, is gaining traction for pulmonary vein isolation (PVI) in the treatment of atrial fibrillation (AF). Assessing acute lesion formation during PFA is critical to optimize procedural outcomes and ensure durable isolation. Objective To evaluate the feasibility of an automated algorithm for analyzing unipolar electrograms (EGMs) before and after PFA delivery to assess tissue response and lesion formation in a porcine epicardial model. Methods EGMs recorded at IR Sant Pau were retrospectively analyzed using a novel proprietary algorithm, PFA Analyzer. This algorithm decomposes single-beat unipolar EGMs to isolate local potentials (LPs), effectively removing far-field and near-field interference, as well as injury currents induced by PFA. Data were collected from high-density electrode arrays placed on the epicardium of six swine hearts subjected to unipolar focal PFA delivery. Baseline and residual electrograms recorded immediately after PFA were analyzed across two regions, with the innermost region representing the immediate ablation zone, and the outer region representing electrodes farther away from the lesion. Results A total of 1152 unipolar EGMs from 9 PFA applications were analyzed. Median and maximum LP energy at baseline and post-PFA were quantified for each region (Table 1). Results showed an increase in LP energy with greater distance from the ablation center, with an average increase of 0.0386 (mV/ms)2. Residual EGMs mapped on color-coded LP amplitude maps (Figure 1) correlated with the presence of injury currents described in previous literature (RS wave phenomenon). Conclusion Automated EGM analysis effectively identifies residual LPs and quantifies their amplitudes in unipolar recordings following PFA. Residual signal presence and amplitude increase proportionally with distance from the ablation zone, underscoring the potential of this approach to assess lesion durability and guide PFA delivery strategies.