BACKGROUND AND OBJECTIVE:As a non-thermal ablation modality, pulsed field ablation (PFA) has been widely applied in solid tumor treatment and cardiac ablation. Multiple factors are known to influence the effects of PFA, including pulse parameters, catheter configurations, and tissue properties. However, limited attention has been paid to the impact of discharge modes on PFA.
METHODS:A sequential discharge mode (M2) was designed based on a multi-electrode ablation catheter and compared with the conventional simultaneous discharge mode (M1). To evaluate the ablation efficacy of different modes, three-dimensional ablation models incorporating two multi-electrode catheter configurations (circular and linear) were established. A comparative numerical simulation analysis was conducted to investigate the electric potential and field distribution characteristics of M1 and M2, followed by animal experiments to validate the simulation results. The comprehensive performance of the two discharge modes was assessed in terms of ablation efficacy and muscle contraction.
RESULTS:M2 demonstrated superior ablation efficacy over M1 in both catheter configurations. For the circular catheter, the minimum lesion depth (M1: 2.08 ± 0.10 mm vs. M2: 2.64 ± 0.46 mm, p = 0.006) was significantly improved, and the uniformity of lesion depth (M1: 0.18 vs. M2: 0.16) was partially enhanced. Similarly, the linear catheter showed improved the minimum lesion depth (M1: 2.81 ± 0.21 mm vs. M2: 3.41 ± 0.44 mm, p = 0.001) and the uniformity of lesion depth (M1: 0.13 vs. M2: 0.11). This advantage may be attributed to M2's higher pulsed energy output and optimized ablation strategy. Notably, although M2 induced slightly higher muscle contraction amplitudes than M1, both modes maintained low contraction levels without significantly compromising ablation efficacy. Specifically, peak accelerations were recorded as M1: 0.030 ± 0.028 g vs. M2: 0.039 ± 0.016 g (p = 0.369) for the circular catheter and M1: 0.031 ± 0.017 g vs. M2: 0.040 ± 0.016 g (p = 0.242) for the linear catheter.
CONCLUSION:Compared to the conventional discharge mode, the sequential discharge mode is recognized as a superior ablation strategy, achieving enhancements in lesion dimensions and uniformity while maintaining a controlled safety profile.