20.500.12556/DiRROS-24665 Modified unipolar return pulsed field ablation in ventricular myocardium BACKGROUND: Various pulsed field ablation (PFA) parameters have been proposed to improve lesion depth. This study evaluated a modified unipolar return PFA system to create deep lesions in healthy and infarcted ventricular myocardia. METHODS: Numerical modeling was used to compare a modified unipolar return PFA system configuration with a conventional unipolar return (skin patch). We then performed ablation in 14 swine (5 with chronic myocardial infarction and 9 healthy). PFA lesions were created in the left ventricle using a focal catheter (4-mm tip) with a return electrode positioned in the inferior vena cava (biphasic, microsecond pulses of 1300 and 1500 V, 1–16 trains). Electroanatomical mapping guided ablation and lesion localization on magnetic resonance imaging were performed 48 hours post-ablation in the infarcted group and at 1 day, 7 days, and 6 weeks post-ablation in the healthy group. RESULTS: Numerical modeling demonstrated that the modified unipolar return PFA system produced deeper lesions with reduced variability compared with the skin patch. In healthy pigs (n=35 lesions), depths of 6.8±1.8 mm and widths of 11.5±4.7 mm were achieved with 8 pulse trains. Depths of 8.2±2.8 mm and widths of 14.0±4.7 mm were achieved with 16 trains. The maximum lesion depths were 8.8 and 11.6 mm for 8 and 16 trains, respectively. In the infarcted cohort (n=22 lesions), all lesions applied to scar tissue penetrated through fibrotic regions, with epicardial involvement observed in 57% of lesions. CONCLUSIONS: The modified unipolar return PFA system effectively creates large lesions and can achieve transmurality in healthy and infarcted animals. Compared with conventional unipolar, it may offer greater lesion depth, width, and consistency. GRAPHIC ABSTRACT: A graphic abstract is available for this article. atrial fibrillation catheter ablation heart ventricles pulmonary veins tachycardia ventricular atrijska ablacija katetrska ablacija srčni ventrikli pljučne vene ventrikularna tahikardija true false true Angleški jezik Slovenski jezik Neznano 2025-12-11 09:03:33 2025-12-11 09:03:34 2025-12-12 03:44:08 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 24. 10. 2025; str. 786-796 no. 10 Vol. 18 Oct. 2025 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 616.1:616.12 1941-3084 10.1161/CIRCEP.125.014006 254692099 RAZ_Terricabras_Casas_Maria_2025.pdf RAZ_Terricabras_Casas_Maria_2025.pdf 1 7991E502D8AB2E70D6CC4EF369416C7B 006b0c0062b6ab4e817acc16afcce5a97a94187138e551299585c4730cb474f1 25b7cdca-d668-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36820 https://www.ahajournals.org/doi/10.1161/CIRCEP.125.014006 1 eb7860d1-d667-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36819 Univerzitetni klinični center Ljubljana 0 0 0