Differential and synergistic effects of right and left atrial ganglionated plexi ablation in patients undergoing cardioneuroablation: results from the ELEGANCE multicenter study

Background: Cardioneuroablation (CNA) treats reflex syncope by ablating ganglionated plexi (GPs) either confined to the right (RA) or left atrium (LA), or accessible from both. We assessed whether GP ablation in one atrium affects parasympathetic modulation in the other and how ablation sequence (RA then LA, or vice-versa) impacts efficacy. Methods: Two propensity-matched groups of patients with reflex syncope or functional bradycardia were analyzed. Group 1 received CNA in the RA first, followed by LA. Group 2 in the reverse order. Results: Thirty-four patients were enrolled. In group 1, RA ablation prompted a heart rate (HR) increase (49.8 ± 10.6 vs. 61.2 ± 13.8 bpm; p < 0.01) that was enhanced after LA ablation (60.3 ± 14.5 vs. 64.5 ± 14.4 bpm; p = 0.02). RA ablation did not reduce PR interval in any patient or modify the Wenckebach point (WP) (596 ± 269 vs. 609 ± 319 ms; p = 0.68), while additional LA ablation reduced PR interval in 3 patients and mean WP (611 ± 317 vs. 482 ± 191 ms; p = 0.03). In group 2, LA ablation increased HR (56.7 ± 6.6 vs. 76.4 ± 13.8 bpm; p < 0.01), with an additional effect of RA ablation (76.0 ± 16.5 vs. 85.4 ± 15.9 bpm; p < 0.01). LA ablation decreased PR interval in 3 patients and mean WP (512 ± 182 vs.399 ± 85 ms; p = 0.01). Further RA ablation did not decrease PR or WP. CNA success was 82% in group 1 and 100% in group 2 (p = 0.552). After 24.5 ± 6.1 months, 2 patients in group 1 vs. no patients in group 2 experienced symptom recurrence. Conclusions: Bi-atrial CNA provides incremental benefits after both RA and LA ablation. Starting ablation in the LA provides the most significant effect on vagal modulation.