P1096Cardioneuroablation changes the type of vaso-vagal response in patients with asystolic reflex syncope

Funding Acknowledgements Centre of Postgraduate Medical Education No. 501-1-10-14-19 Background. Cardioneuroablation (CNA) - ablation of ganglionated plexi (GP) to eliminate or reduce parasympathetic overactivity, has been recently proposed as a new therapeutic method in patients with vaso-vagal syncope (VVS) due to cardioinhibitory or mixed mechanism. Purpose. To assess the impact of CNA on the type of VV response during tilt testing (TT). Methods. The study group consisted of the first 20 patients (7 males, mean age 38 ± 9 – year – old) enrolled in the ongoing prospective Roman study (NCT 03903744). All patients had a history of ECG documented syncope due to asystole and confirmed asystolic form of VVS at baseline TT. CNA was performed using electroanatomical system Carto 3 and radiofrequency applications delivered in the right and left atrium at the right anterior GP and right inferior GP sites. The second TT was performed three months later. Resting heart rate (HR) and heart rate variability parameter (SDDN) were also assessed. Results. At baseline TT, nineteen patients had cardioinhibitory syncope (asystole ranging from 3 to 60 s) (sinus node arrest – 17 patients, A-V block – 2 patients) and 1 had mixed form of VVS (asystole lasting 3 s preceded by hypotension). During three-month follow-up no syncopal episodes were noted. At the 3-month TT, 6 (30 %) patients had no syncope whereas the remaining 13 (65 %) had syncope – twelve (60 %) due to vasodepressor mechanism and only one (5 %) due to asystole - as before CNA. One patient did not have TT because of pregnancy. Mean resting HR after CNA was significantly faster and SDNN significantly lower than before the procedure (82 ± 9 vs 69 ± 11 beats/min, p = 0.0004 and 74 ± 22 vs 143 ± 40 ms, p = 0.00003, respectively) and these changes were was similar in those who fainted during second TT and those who did not (82 ± 11 vs 81 ± 4 beats/min, p = NS and (75 ± 2 vs 77 ± 18 ms, p = NS, respectively). Conclusions. CNA profoundly affects the type of VV reaction causing normalization of the response to tilting or changing cardiodepression to vasodepression. These effects are also depicted by changes in HR and heart rate variability. Elimination of TT-induced reflex asystole may prevent clinical recurrences of syncope during short-term follow-up. These findings encourage to conduct further studies involving CNA since this method appears to be effective and obviates the need for pacemaker implantation in young people with reflex asystolic syncope.