Impact of high-power, short-duration radiofrequency ablation on first-pass binodal parasympathetic denervation during cardioneuroablation
S Stec, A Wileczek, J Sledz, M Kornaszewska, J KornaszewskaAbstract
Introduction
The impact of energy settings on the effectiveness of parasympathetic denervation during cardioneuroablation (CNA)—as assessed by the elimination of vagal reflexes induced by extracardiac vagal nerve stimulation (ECVS)—has not yet been investigated. We aimed to evaluate the impact of high-power, short duration (HPSD) compared to low-power, long-duration (LPLD) ablation on procedural characteristics and the first-pass (FP) rate of complete binodal parasympathetic denervation, as determined by ECVS before and after CNA.
Methods
Patients with isolated vagally mediated bradyarrhythmias (VMBs) were enrolled for their first anatomically guided, biatrial, binodal CNA performed under general anesthesia. Patients were assigned to one of 2 groups based on ablation strategy: the LPLD group (the last 100 patients treated between January 2024 and December 2024) and the HPSD group (the first 50 patients treated between January and April 2025). The endpoint of CNA was defined as the elimination of ECVS-induced vagal reflexes, including sinus arrest lasting > 1.5 seconds, sinus bradycardia below 40 bpm, or advanced atrioventricular block (Mobitz type II or complete atrioventricular block). ECVS was performed unilaterally before the procedure and, when feasible, bilaterally from the internal jugular vein after CNA. Energy settings were as follows: in the LPDP group, 30-35 W for 30-45 seconds per application, totaling 180-240 seconds per ganglionated plexi (GP) region; in the HPSD group, 45-50 W for 15 seconds per application, totaling 90-120 seconds for each GP region. All procedures were performed using irrigated-tip ablation catheters guided by a 3D electroanatomical mapping system.
Results
Binodal parasympathetic denervation was successfully achieved in all cases. Compared to the LPLD group (mean age, 50.3±13.2 years; 47% female), the HPSD group (mean age, 51.3±15.2 years; 44% female) demonstrated shorter procedure times (55 [40-80] min vs 70 [55-110] min), lower total RF delivery times (725 [450-1200] s and 950 [800-1500] s), and a lower rate of FP failure (2% vs 22%) (all p-values < 0.01). The 6-month recurrence rate of VMBs was similar between HPSD and LPLD groups (4% vs 6%, p=NS). The incidence of major but non–life-threatening complications, all managed conservatively, was low and comparable between groups (2% vs 3%, p=NS).
Conclusion
In this prospective observational cohort study, the HPSD CNA technique significantly reduced both procedure and RF delivery times and was associated with a higher rate of FP binodal parasympathetic denervation compared to LPLD CNA. No safety concerns were identified with HPSD ablation; however, its long-term efficacy warrants further investigation.