![]() There are several recent reports showing minimal to minor effects on nerves and esophagus compared to RFA energy ( 27– 29) as well as a reduction in pulmonary vein stenosis when energy is applied directly in the veins ( 30). In addition, PFA has the potential to increase procedural efficiency and reduce procedure times ( 22, 23). Second, PFA is a field-based technology and is not critically dependent on direct electrode-tissue contact and contact force ( 25, 26). ![]() First, it offers the potential for greater safety and less collateral damage compared with thermal ablation technologies ( 22– 24). There are several potential advantages of PFA compared with existing thermal ablation modalities. Irreversible electroporation was (re)introduced as a promising method for cardiac ablation in 2007 ( 11) and has since been shown to be a successful procedure for ablation of both atrial ( 2, 12– 17), and ventricular tissues ( 18– 21). Electroporation was shown to be involved with DC ablations as well as in defibrillation, as a response to the applied electric shocks ( 9, 10). DC ablation was used for cardiac ablation, before radiofrequency ablation (RFA) became the dominant ablation modality ( 7, 8). The main mechanism of cell death associated with PFA is irreversible electroporation (IRE) in which cell membranes are disrupted by exposure of cells to intense short electric field pulses, causing cells to lose their abilities to maintain or recover homeostasis, leading to cell death ( 4– 6). Pulsed Field Ablation (PFA) is an emerging non-thermal energy modality for intracardiac catheter-based ablation used for treatments of cardiac arrhythmias ( 1– 3). These findings, albeit preliminary, from a limited number of hearts suggest that treatments in humans with parameters optimized in pigs should result in equal or greater lesions. The median threshold value was 368 V/cm in porcine hearts (( N = 35 lesions in n = 9 hearts) cm for 48 × 100 μs pulses.ĭiscussion: The values obtained are compared with an extensive literature review of published lethal electric field thresholds in other tissues and were found to be lower than most other tissues, except for skeletal muscle. ![]() Results: The median threshold was 535 V/cm in porcine (( N = 51 lesions in n = 6 hearts) and 416 V/cm in the human donor hearts (( N = 21 lesions in n = 3 hearts) for the biphasic waveform. The lethal electric field threshold, anisotropy ratio, and conductivity increase by electroporation were determined by numerical modeling, comparing the model outputs with segmented lesion images. Methods: In the study, lesions were generated by applying IRE in porcine and human left ventricles using a pair of parallel needle electrodes at different voltages (500–1500 V) and two different pulse waveforms: a proprietary biphasic waveform (Medtronic) and monophasic 48 × 100 μs pulses. Lethal electric field threshold for IRE is a tissue property that determines treatment feasibility and enables the development of new devices and therapeutic applications, but it is greatly dependent on the number of pulses and their duration. The main mechanism of action is irreversible electroporation (IRE), a threshold-based phenomenon in which cells die after exposure to intense pulsed electric fields. Introduction: Pulsed field ablation is an emerging modality for catheter-based cardiac ablation. 3Department of Surgery, Visible Heart® Laboratories, University of Minnesota, Minneapolis, MN, United States.2Cardiac Ablation Solutions, Medtronic, Inc., Minneapolis, MN, United States.1Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.Bor Kos 1, Lars Mattison 2, David Ramirez 3, Helena Cindrič 1, Daniel C.
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