P1097Heart rate acceleration is a poor surrogate of complete parasympathetic denervation of sinus node during cardioneuroablation

Abstract

Background Ablation of superior paraseptal ganglionic plexi is invariantly associated with the acceleration of sinus rhythm. This is considered a favourable sign during cardioneuroablation for the treatment of recurrent neurally-mediated cardioinhibitory syncope or symptomatic sinus bradycardia. Purpose In this retrospective study, we investigated whether the magnitude of sinus rhythm acceleration corresponds with directly assessed sinus nodal parasympathetic denervation. Methods The study included 48 patients (age: 39 ± 13 years, 58% males) who underwent cardioneuroablation in general anaesthesia. The procedural endpoint was non-responsiveness (i.e. loss of original cardioinhibitory response) of the sinus node to extracardiac high-frequency stimulation of the vagal nerve. The magnitude of sinus rhythm acceleration was compared between patients who reached or did not reach this endpoint. Results All patients had positive atropine test (baseline heart rate: 65 ± 14 bpm; post-atropine: 109 ± 22 bpm). Complete sinus nodal denervation as assessed by vagal nerve stimulation was achieved in 44/48 (92%) patients. Intraprocedurally, heart rate accelerated from 54 ± 11 to 85 ± 14 bpm (difference: 31 ± 10; median 29; interquartile range: 24–40; total range: 13–61 bpm). This change did not correlate with age and was not related to pre-procedural post-atropine sinus rhythm acceleration. There was no difference in heart rate acceleration between the patient with and without sinus nodal denervation (Figure). Conclusions Sinus rhythm acceleration is not reliable endpoint for cardioneuroablation. Guidance by extracardiac vagal nerve stimulation may help to tailor the procedures to increase the clinical success rate and, at the same time, to avoid patient overtreatment. Abstract Figure.

Long‐term outcomes of cardioneuroablation with and without extra‐cardiac vagal stimulation confirmation in severe cardioinhibitory neurocardiogenic syncope

“…Immediate results may be achieved by eliminating superficial fibers, but long‐term outcomes depend on the disappearance of deep neural bodies. There are numerous instances where, despite modifications in all EP parameters, ECVS reveals a significant residual vagal response, 28 often leading to clinical recurrence. In this study, we found that although there was no statistically significant difference in the electrophysiological parameters of acute vagal denervation (as shown in Table 3), there was a significant difference in long‐term outcomes, suggesting that immediate electrophysiological response alone may not be enough to predict the long‐term efficacy of CNA.…”

To the Editor—Atropine: Hero or villain in cardioneuroablation?

“… 3 CNA must be finished only after complete vagal response abolishment, and no CNA may be considered successful without this confirmation as the main endpoint. In case of residual vagal response, CNA must be expanded, ablating additional atrial fibrillation nests, 4 , 5 , 6 until complete abolishment. Residual innervation must be disclosed to the patient, as reinnervation/recurrence may occur.…”