Preclinical Evaluation of a Novel Single-Shot Pulsed Field Ablation
System for Pulmonary Vein and Atrial Ablation
Introduction : Pulsed field ablation (PFA) is a
non-thermal ablative strategy that achieves cell death via
electroporation. Herein, we investigated the preclinical safety and
efficacy of PFA using two novel 8-French, 16-electrode spiral
PFA/mapping catheters (ElePulse, CRC EP, Inc). M
ethods : Bipolar PFA (>1.8 kV) was
performed using 30 sec, single-shot, QRS-gated applications. Altogether,
94 atrial structures were ablated in 23 swine, 1 canine, and 1 ovine,
including right and left atria and atrial appendages, pulmonary veins,
and superior and inferior (IVC) vena cavae. We also examined the impact
of PFA on phrenic nerve (14 swine) and on a deviated esophagus after
delivery of PFA from inside the IVC (5 swine). Results: All
applications were single-shot without catheter repositioning. Minimal
microbubbling was observed without significant skeletal muscle
twitching/activation (mean acceleration: 0.05 m/s 2).
There was marked reduction in post- versus pre-PFA atrial electrogram
amplitude (0.17±0.21 mV vs. 1.18±1.08 mV; P<0.0001).
Durable conduction block was demonstrated up to 3 months in all targeted
tissues. Lesions were contiguous and transmural, measuring 25±9 mm x
21±7 mm without any thermal effects. Magnetic resonance, gross, and
histologic examinations of the brain, rete mirabile, and kidneys
revealed no thromboembolism. No acute/long-term phrenic nerve
dysfunction was encountered. Though within 2 hours of ablation,
histologic examinations of the esophagus revealed acute PFA-related
changes in the muscular layer, these completely resolved by 21±5 days.
Conclusion : A novel, single-shot, spiral PFA system
is capable of safely creating large, durable atrial lesions without
significant adverse effects on the phrenic nerve or the esophagus.