Electrical impedance spectroscopy facilitates quantitative depth monitoring of pulsed field ablation: An impedimetric approach with preclinical validation.

BACKGROUND

Pulsed field ablation (PFA) is an emerging therapy for cardiac ablation, where ablation depth (D) is critical to procedural success. However, real-time intra-procedural assessment of D remains a challenging task.

OBJECTIVE

Electrical impedance spectroscopy (EIS) has been proposed to predict the ablation zone, but its applicability and mechanism for quantifying D is still unclear.

METHODS

Monopolar and bipolar PFA were conducted via 2 catheter types, along with in situ EIS measurements. The change rate of low-frequency resistance (LFR), derived from Cole-Cole modeling of EIS data, was used to evaluate D in both in vitro (205 potato samples) and in vivo canine models (n = 5).

RESULTS

LFR vs Ds followed a classical Gompertz growth model within 0∼15 mm (R2 = 0.8789). A quadratic function provided a good fit for evaluating Ds within 1∼9 mm (R2 = 0.7561). Furthermore, LFR5min could detect a depth difference of approximately 0.8 mm in canine cardiac ablation (P = .0003).

CONCLUSIONS

LFR5min robustly correlated with PFA lesion depth, fitting quantitative quadratic and Gompertz models. Validated in vivo in a clinically relevant canine cardiac model, LFR5min resolved sub-millimeter depth differences, positioning it as a promising intra-operative metric for real-time PFA guidance.