Clinical Electrophysiology -> Syncope & Bradycardia: -> Experimental Methods D-MP09 - Atrial Fibrillation: From Pathophysiology to Epidemiology to Treatment Options (ID 36) Moderated ePoster

D-MP09-06 - Seeking The Right Atrial Sweet Spot For Vagal Denervation Of Sinus Node During The Cardioneuroablation (ID 8)

 D. Wichterle: Nothing relevant to disclose.


Background: Radiofrequency catheter ablation of superior paraseptal ganglionic plexi results in variable degree of sinus nodal denervation. Reasonable effect can be achieved by ablation from the aspect of right atrium only.
Objective: We prospectively sought the right atrial ablation site with the maximum effect on vagal modulation of sinus node.
Methods: The study included 16 patients (age: 46±14 yrs, 56% males) who underwent cardioneuroablation for recurrent reflex cardioinhibitory syncope or symptomatic sinus bradycardia in general anesthesia. Semicircular lesion was created in posteroseptal quadrant of superior vena cava ostium. This lesion was composed of 6 equidistantly distributed ablation sites (30W / 30s / 20ml/min) numbered in ascending order from #1 (posterolateral) to #6 (pure septal) positions. Patients were randomly (1:1) assigned to mutually opposite direction of ablation (from site #1 to #6 or from site #6 to #1). Sinus rate and the response to extracardiac right vagal nerve high-frequency stimulation (50Hz / 0.05ms / 1V/kg[<70V] / 5s) were recorded at baseline and after each radiofrequency energy delivery.
Results: Study protocol ablations overall resulted in sinus acceleration (84±13 vs. 62±13 bpm, P <0.0001) and attenuation of inducible sinus arrests (maximum pause: 1.9±1.9 vs. 6.5±3.2s, P <0.0001). Temporal development of outcome measures with progression of ablation is shown in the Figure.
Conclusion: Segmental ablation of superior vena cava ostium results in significant modification of the vagal input into the sinus node. Posterior ablations alone (1-3 lesions) conveyed maximum effects compared to septal lesions that were associated with partial effects.