Computational Assessment of Electrical and Thermal Effects of Epicardial Pulsed Field Ablation Adjacent to Stented Arteries.

BACKGROUND

Current ablation strategies for the treatment of cardiac arrhythmias remain suboptimal. Treating cardiac arrhythmias using epicardial pulsed field ablation (PFA) selectively targets ganglionated plexi (GPs) within epicardial fat, offering a promising alternative to thermal ablation. Previous computational studies lacked physiological realism, excluding catheter geometry, fluid flow and post-PFA thermal latency. This study aimed to develop a realistic 3D epicardial PFA model integrating a clinical catheter, clinical PFA parameters and a sequentially coupled electro-thermal-fluid dynamics model, including thermal latency, to assess electrical and thermal collateral effects near stented coronary arteries.

METHODS

The model included epicardial fat, myocardium, blood, and the left circumflex artery containing a metallic stent positioned 0.25 mm beneath the catheter electrodes. Pulses of 1000, 2000, and 2500 V (60 pulses × 100 µs, 1 Hz) were simulated to analyze electric field distribution, PFA-induced lesion volume, temperature evolution, and Arrhenius-based thermal damage, including a 90 s post-pulse period to account for thermal latency. The PFA-threshold of 1000 V/cm was considered.

RESULTS

The artery reduced PFA-induced lesion size mainly by occupying fat tissue volume, while the stent shielded the lumen without altering fat lesion volume. The presence of a stent produced localized electric field enhancement at the arterial wall, with up to 3.83% of the arterial wall volume affected by PFA in the worst-case configuration. At clinical settings (1000 V), temperature remained below 40 °C and no collateral damage occurred. Voltages > 2000 V increased arterial wall heating, with thermal damage expanding up to five-fold during latency in the epicardial fat. Myocardium remained unaffected in all cases.

CONCLUSIONS

The computational model developed in this study indicates that clinically relevant PFA parameters (1000 V) produce localized electric field enhancement at the stent-artery interface, resulting in limited collateral electrical effects in the arterial wall, while avoiding collateral thermal effects and preserving the myocardium. However, the use of higher pulse voltages can lead to delayed thermal damage within the epicardial fat.