Understanding the Biophysics of Pulsed Field Ablation: An In-Vitro Study
Abstract 2297748, presented at Western Atrial Fibrillation Symposium 2026
To evaluate the effects of tissue thickness, catheter‚ tissue contact, lateral lesion overlap, and repeated energy applications on lesion size using the FARAPULSE‚Ñ¢ PFA Platform (Boston Scientific, Marlborough, MA) in a novel in-vitro model.Myocardial tissue slices were submerged in a custom immersion tank containing warm saline (resistivity 126 ohm-cm) and ablated at 2000 V. Tissue thicknesses studied included 1.5 mm, 3 mm, 4.5 mm, 6 mm, and 10 mm. One, two, or three energy applications were delivered per site. Catheter‚Äìtissue contact was varied from ‚àí2 mm (compression) to +2 mm (gap). Lateral overlap was assessed by creating paired lesions with 25%, 50%, or 75% overlap. Lesion area was quantified and compared across conditions.Lesion area increased significantly with three applications compared with one in intermediate-thickness tissue (3 mm and 4.5 mm; P < .05). In 1.5-mm slices, closer catheter contact yielded significantly larger lesions (P = .005). Reduced lateral overlap between adjacent lesions increased total lesion area in 1.5-mm slices (P = .004), an effect not observed in thicker tissues.PFA lesion characteristics are influenced by substrate thickness, catheter-to-tissue distance, lateral overlap, and the number of applications. These findings contribute to a deeper understanding of PFA lesion biophysics and may inform strategies for optimizing procedural efficacy.
