Electric field effects of pulsed field ablation through adjacent non-cardiac tissues in an in vitro hybrid model

Background Endocardial ablation of atrial arrhythmias may occasionally produce insufficient lesion depth. Pulsed-field ablation (PFA) may generate measurable electroporation effects beyond interposed non-cardiac tissues, but field propagation across such tissues remains poorly understood. Methods We introduced an in vitro model to visualize electroporation in potato slices overlaid by ex vivo porcine tissues, including esophagus, aortic root, and pulmonary trunk. A control group received PFA without any barrier. Lesions were created using a commercially available multielectrode PFA catheter across three subsets using different numbers of applications. Depth of irreversible electroporation, total lesion depth (irreversible and reversible electroporation), and irreversible electroporation surface area were quantified. Results Across 60 lesions, two-way ANOVA showed significant effects of barrier tissue and number of applications on all primary endpoints (all p < 0.001). A significant tissue-by-dose interaction was observed only for total lesion depth ( p < 0.001). Compared with control, irreversible electroporation depth was lower beneath the esophageal, aortic root, and pulmonary trunk by 2.01, 2.21, and 1.44 mm, respectively. Total lesion depth was unchanged beneath the esophagus but lower beneath the aorta and pulmonary trunk. Irreversible electroporation area was greater beneath the esophagus, lower beneath the aorta, and unchanged beneath the pulmonary trunk. Conclusion Our findings show that measurable electroporation effects can be produced in a hybrid potato model beyond ex vivo non-cardiac tissues, with tissue-dependent differences in lesion depth and lesion area.