Parameter-dependent modulation of cardiomyocyte metabolic activity by microsecond circular pulsed electric fields

Pulsed-field ablation (PFA) is an emerging technique for cardiac arrhythmia treatment, but the effects of varying microsecond pulsed electric fields (μsPEFs) parameters on cardiomyocyte metabolic activity and survival remain incompletely understood. To systematically investigate how voltage intensity, pulse packet number, and the number of applications influence metabolic activity and viability. AC16 human cardiomyocytes were exposed to μsPEFs with varying voltages, pulse packets, and application numbers. Metabolic activity was assessed by CCK-8 assays at multiple time points post-intervention. Cell death was analyzed by Annexin V-FITC/PI flow cytometry. Low-voltage μsPEFs (≤ 1400 V) induced minimal metabolic suppression with partial recovery at 24 h. Higher voltages (≥ 1600 V) caused biphasic metabolic responses, peaking at 6 h then sharply declining by 24 h. Increasing pulse packets and applications led to progressive metabolic suppression, especially at higher voltages. Flow cytometry revealed voltage-dependent increases in apoptotic and necrotic cardiomyocytes, with significant viability loss at ≥ 1600 V. Cardiomyocyte metabolic activity and survival exhibit clear dose-dependent sensitivity to μsPEFs parameters, with distinct voltage and energy thresholds for irreversible injury. Precise modulation of μsPEFs settings is crucial to optimize therapeutic efficacy and safety. These findings inform future preclinical and clinical μsPEFs ablation protocols.