Monopolar biphasic focal pulsed field ablation directly at the atrioventricular junction and from within the noncoronary cusp: The PFA-CONDUCT study

BACKGROUND: The efficacy and safety of monopolar biphasic focal pulsed field ablation (F-PFA) in close proximity to the atrioventricular (AV) node remain unknown. OBJECTIVE: This study aimed to describe the effect of direct or indirect F-PFA application at the AV junction. METHODS: In pigs, F-PFA (Centauri, CardioFocus) was applied directly at the AV junction (n = 3) and indirectly from within the aortic noncoronary cusp (NCC) (n = 5), followed by macroscopic gross and histologic analysis. In 5 patients planned for a pace-and-ablate strategy, F-PFA was applied at the AV junction. In 1 patient with recurrent para-Hisian atrial tachycardia and previously failed ablation, F-PFA was applied from within the NCC. RESULTS: In pigs, direct F-PFA applications at the AV junction were associated with junctional beats and resulted in complete AV block after 2-3 F-PFA applications. Tissue histology revealed a lesion depth of approximately 8 mm with minor hemorrhage and leukocyte infiltration. F-PFA from within the NCC resulted in a transient increase in the AV node's Wenckebach cycle length and 1 pig had transient AV block, which recovered within 10 minutes. In 5 patients undergoing pace-and-ablate strategy, F-PFA applications at the AV junction resulted in sustained AV block. In 1 patient, application of F-PFA from within the NCC resulted in termination and noninducibility of a recurrent incessant para-Hisian atrial tachycardia without AV block. There were no immediate or long-term complications. CONCLUSION: F-PFA directly at the AV junction results in nonreversible AV block. F-PFA from within the NCC may represent a promising strategy for treating para-Hisian arrhythmias while preserving AV conduction.