An ultrasimplified technique to perform cardioneuroablation: results from a prospective observational study

Background

Cardioneuroablation (CNA) has emerged as a promising therapeutic strategy for patients with reflex syncope. However, current approaches remain technically complex and heterogeneous.

Purpose

To prospectively evaluate the feasibility, efficacy, and safety of an ultrasimplified CNA protocol in reducing reflex syncope recurrence.

Methods

Twenty-six patients (mean age 43.9 ± 16.4 years) with ≥3 reflex syncope episodes in the previous 12 months underwent CNA. We measured baseline parameters including heart rate (HR), AH interval, sinus node recovery time (SNRT), and Wenckebach point. Electroanatomical mapping of both atria was performed using a multipolar catheter (Advisor HD Grid, Abbott) with the EnSite X mapping system to identify low- and high-amplitude fractionated electrograms at sites consistent with ganglionated plexi (GP) regions. A second frequency map was then created using the Omnipolar Technology Near Field (OTNF; Abbott) by adjusting the frequency window to maximize the isolation of high frequency areas: peak frequency was set at 600 Hz to highlight the smallest areas with high-frequency spectrum in the anatomic GP positions. In case of discordance between the two maps, the areas with high-frequency spectrum were accepted as potential GP sites and treated with radiofrequency ablation. After tracking the right phrenic nerve course, radiofrequency applications were delivered using the 3.5-mm tip ablation TactiCath catheter (Abbott), guided by the Lesion Index, local potential eliminations and HR acceleration ≥20% above baseline.

Post-ablation HR, AH interval, SNRT, and antegrade Wenckebach point were re-evaluated, followed by an atropine test (0.04 mg/kg IV). Procedural success was defined as a post-ablation HR increase ≥20% above baseline combined with a blunted response to atropine infusion (<20% increase).

Results

Mean procedural and fluoroscopy times were 94 ± 16 and 18.5 ± 7.8 mn, respectively, with a mean radiation dose of 392 ± 245 cGy.

Left atrial dwell time averaged 23.7 ± 5.8 mn, with mapping and ablation times of 8.2 ± 2.4 and 15.5 ± 4.9 mn, respectively.

All post-ablation electrophysiological parameters significantly shortened compared with baseline: AH interval (78 ± 22 vs 98 ± 23 ms), Wenckebach point (343 ± 60 vs 450 ± 119 ms), SNRT(1028 ± 235 vs 1261 ± 271 ms), all p < 0.005. Basal HR increased from 60 ± 12 bpm to 89 ± 17 bpm, while post-ablation atropine HR acceleration was blunted (7.70 ± 5.79 bpm), all p < 0.005.

At a mean follow-up of 15 ± 7 months, syncope recurred in only 1 patient, and 8 patients reported transient palpitations that resolved within 2 months. No major complications occurred.

Conclusion

This ultrasimplified CNA approach proved feasible, safe, and effective in reducing recurrent reflex syncope episodes over a mean 15-month follow-up.Left atrium high frequencies mapRight atrium high frequencies map