ABSTRACT Background Pulsed‐field ablation (PFA) offers myocardial selectivity with minimal thermal injury, but depth for ventricular lesions may be insufficient or heterogeneous at clinically tolerable field strengths. Calcium electroporation—local calcium chloride (CaCl₂) infusion after PFA—may amplify electroporation‐mediated cell death while maintaining low energy settings. Objective To determine whether immediate post‐PFA CaCl₂ infusion enhances acute and chronic ventricular lesion formation in vivo. Methods Nine swine underwent focal ventricular PFA (750–1000 V, biphasic, 20 μs × 50 pulses, 200 ms interpulse) via an irrigated focal catheter and benchtop electroporator. Immediately post‐PFA, lesions were randomized to saline, 0.2 g Ca, or 0.4 g Ca infused locally through the catheter tip. Acute hearts were explanted for TTC analysis; surviving animals were studied at 7 days for chronic lesion geometry. Results Among 41 acute lesions (17 control, 12 Ca 0.2 g, 12 Ca 0.4 g), Ca 0.4 g increased dark‐zone depth (3.5 ± 1.4 vs. 2.3 ± 0.8 mm; p = 0.038) and pale‐zone depth (2.6 ± 1.3 vs. 1.3 ± 0.8 mm; p = 0.011) versus control. At 7 days ( n = 33 lesions), Ca 0.4 g produced larger scars than control (width 11.6 ± 2.1 vs. 10.0 ± 1.9 mm; p = 0.027; depth 4.2 ± 1 vs. 3.0 ± 0.8 mm; p < 0.001; volume 193.6.4 ± 82.3 vs. 109.4 ± 48.2 mm³; p = 0.001). Conclusions Local CaCl₂ infusion after ventricular PFA significantly augments acute electroporation effect and chronic lesion size at low output, supporting facilitated PFA as a strategy for deeper, more durable ventricular ablation.
Koya et al. (Sun,) studied this question.