Modified unipolar return pulsed field ablation in ventricular myocardium

Terricabras Casas, Maria (author), Lombergar, Peter (author), Escartin, Terenz (author), Kos, Bor (author), Krahn, Philippa R. (author), Barry, Jennifer (author), Wright, Graham (author), Jarm, Tomaž (author), Štublar, Jernej (author), Kranjc, Matej (author), Coulombe, Nicolas (author), Mattison, Lars M. (author), Sigg, Daniel C. (author), Miklavčič, Damijan (author), Verma, Atul (author)

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.

• Language: English
• Keywords: atrial fibrillation, catheter ablation, heart ventricles, pulmonary veins, tachycardia ventricular
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: Str. 786-796
• Numbering: Vol. 18, no. 10
• PID: 20.500.12556/RUL-175368
• UDC: 616.1:616.12
• ISSN on article: 1941-3084
• DOI: 10.1161/CIRCEP.125.014006
• COBISS.SI-ID: 254692099
• Publication date in RUL: 24.10.2025

Record is a part of a journal

• Title: Circulation : arrhythmia and electrophysiology
• Shortened title: Circ. Arrhythm. electrophysiol.
• Publisher: Lippincott Williams & Wilkins
• ISSN: 1941-3084
• COBISS.SI-ID: 522451737

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: atrijska ablacija, katetrska ablacija, srčni ventrikli, pljučne vene, ventrikularna tahikardija

Projects

• Funder: Medtronic