Novel focal-bipolar pulsed field ablation for treatment of accessory pathways located near the bundle of his

Background Radiofrequency (RF) ablation of parahisian accessory pathways (AP) can be associated with a substantial risk of atrioventricular (AV) block. Pulsed field ablation (PFA) may enable selective myocardial injury with possible sparing of nearby conductive tissues. We report the first clinical experience with novel focal-bipolar PFA for treatment of AP located in the proximal distance to the bundle of His. Purpose To evaluate the safety and feasibility of the focal-bipolar PFA for AP located near the bundle of His. Methods Consecutive patients undergoing first-time ablation of an AP located near the bundle of His were included in the study. A series of focal-bipolar PFA applications were delivered at the site of AP location. Procedural success was defined as complete elimination of AP conduction. Efforts were made to detect any AV nodal function abnormalities following PFA. Results Six patients (mean age 32 ± 7 years; 3 males) were included in the study. Two patients had an anteroseptal AP, two had a parahisian AP, one had a midseptal AP, and one had a right anterior AP. In three patients, initial RF applications were attempted but proved ineffective (mean power 50±0 W, mean duration 111±82 s) and were followed by successful conversion to focal-bipolar PFA, whereas the remaining three patients underwent focal-bipolar PFA as an initial step. The mean number of PFA applications was 11±3, and the mean procedure time was 58±23 minutes. The PFA voltage ranged between 1400 and 2000 V. Acute success was achieved in all patients and no procedure-related complications, including AV node damage were observed. During a follow-up lasting 2±1 months, preexcitation reoccurred in one patient, while the remaining five maintained normal AV conduction. Conclusion Focal-bipolar PFA is feasible and appears to be a safe therapy for APs located near the bundle of His.