Background: Pulsed field ablation (PFA) is a novel technique for treating cardiac arrhythmias that has gained significant attention due to its faster procedural times and enhanced safety profile. However, its efficacy remains comparable to that of thermal ablation methods. In this context, computational modeling can offer valuable insights into lesion formation, particularly in thicker ventricular tissues. Current state-of-the-art models often fail to accurately predict lesion dimensions, highlighting the need for further model refinement.
Methods: We developed a 3D open-chest porcine geometry that mimics an experimental result, following the model in [1]. Ventricular fiber orientation was incorporated using a rule-based algorithm, and anisotropic electrical conductivity properties were assigned based on literature values. Lesion size was estimated using a lethal electric field threshold, and the resulting width-to-depth anisotropy ratios were compared with experimental measurements reported in [1].
Results: We found that using literature-reported anisotropic electrical conductivity values for porcine tissue produced anisotropy ratios similar to those observed in the isotropic case presented in [1]. However, increasing conductivity along the fiber direction, according to published data, results in lesions with a comparable anisotropy ratio, thus still not matching the experimentally observed values.
Discussion: Our findings indicate that incorporating anisotropic electrical conductivity alone is insufficient to accurately reproduce lesion geometry resulting from ventricular PFA. This suggests that additional cellular-level mechanisms significantly influence lesion formation and should be integrated into computational models to enhance predictive accuracy.
[1] Petras, A., Amoros Figueras, G., Moreno Weidmann, Z., Garcia-Sanchez, T., Vilades Medel, D., Ivorra, A., Guerra, J. M., & Gerardo-Giorda, L. (2025). Is a single lethal electric field threshold sufficient to characterize the lesion size in computational modeling of cardiac pulsed-field ablation? Heart Rhythm O2. doi:10.1016/j.hroo.2025.02.014