Catheter Ablation as a Treatment for Vasovagal Syncope: Long‐Term Outcome of Endocardial Autonomic Modification of the Left Atrium

This study aims to evaluate the safety and efficacy of zero-ray radiofrequency ablation of the cardiac autonomic ganglionic plexus (GP) for treating vasovagal syncope (VVS) in young individuals undergoing high-intensity physical training. We retrospectively analyzed data from 35 young individuals with recurrent syncope (≥3 syncopal episodes within the year prior to the procedure) who underwent GP ablation at our hospital between May 2021 and January 2023. Among them, 33 (94.3%) were male, with a mean age of 22.7 ± 4.6 years. Systemic diseases and/or organic heart conditions that could cause syncope were excluded through comprehensive examinations upon admission. GP ablation was performed in patients with a positive upright tilt test. During the procedure, zero-ray septal puncture was guided by intracardiac ultrasound, and the GP was localized using the anatomical approach (AA) as the ablation target. The ablation endpoint was defined as an increase in heart rate to approximately 90 beats per minute. The safety and efficacy of the procedure were assessed by comparing preoperative and postoperative data, including heart rate, sinus node recovery time, atrioventricular (AV) Wenckebach point, heart rate variability (HRV), deceleration capacity of the heart (DC), and the occurrence of arrhythmias. No intraoperative or postoperative complications were observed with zero-ray intracavitary ultrasound-guided GP ablation. Postoperatively, the sinus node recovery time and AV Wenckebach point were significantly shorter compared to preoperative values (P < 0.001). Both the postoperative mean ECG heart rate and the 12-month postoperative Holter mean heart rate were significantly higher than preoperative levels (P < 0.001). Additionally, sDANN-24, rMSSD, and deceleration capacity (DC) were significantly reduced postoperatively (P < 0.001). The follow-up period ranged from a minimum of 15 months to a maximum of 35 months. Within one year after surgery, two cases experienced a single episode of syncope, and one case reported a single episode of a syncopal premonitory aura. In the patient with a syncopal premonitory aura, outpatient ECG and Holter monitoring showed no abnormalities. The patient who experienced syncope was readmitted for further evaluation, including ECG, Holter monitoring, and an upright tilt test, which was negative. Two postoperative cases (one with a syncopal premonitory aura and one without syncope) exhibited second-degree type II AV block on Holter monitoring, which occurred during nocturnal sleep. Despite this, both groups were able to continue high-intensity physical training with significant symptomatic improvement. Zero-ray cardiac GP ablation is a radiation-free, minimally invasive, safe, and effective treatment for young VVS patients undergoing high-intensity physical training.

Catheter ablation of ganglionated plexi (GPs) performed as cardioneuroablation in the left atrium (LA) has been reported previously as a treatment for vasovagal syncope (VVS). However, the efficacy and safety of catheter ablation in the treatment of VVS remains unclear. The objective of this study is to explore the efficacy and safety of catheter ablation in the treatment of VVS and to compare the different ganglion-mapping methods for prognostic effects. A total of 108 patients with refractory VVS who underwent catheter ablation were retrospectively enrolled. Patients preferred to use high-frequency stimulation (HFS) (n = 66), and anatomic landmark (n = 42) targeting is used when HFS failed to induce a positive reaction. The efficacy of the treatment is evaluated by comparing the location and probability of the intraoperative vagal reflex, the remission rate of postoperative syncope symptoms, and the rate of negative head-up tilt (HUT) results. Adverse events are analyzed, and safety is evaluated. After follow-up for 8 (5, 15) months, both HFS mapping and anatomical ablation can effectively improve the syncope symptoms in VVS patients, and 83.7% of patients no longer experienced syncope (<0.001). Both approaches to catheter ablation in the treatment of VVS effectively inhibit the recurrence of VVS; they are safe and effective. Therefore, catheter ablation can be used as a treatment option for patients with symptomatic VVS.

ORAL PRESENTATION

Selective cardioneuroablation of the posteromedial left ganglionated plexus for drug-resistant swallow syncope with functional atrioventricular block

Ganglionated plexus ablation of the left atrium for refractory vasovagal syncope: Analysis of the Safety, Effectiveness and Related Factors.

Right anterior ganglionated plexus: The primary target of cardioneuroablation?

Background Vasovagal syncope is the most common cause of syncope across all age groups. Previous studies have demonstrated that targeted ablation modification of specific ganglionated plexi can attenuate vagally mediated cardiac inhibition, thereby reducing syncope episodes. However, catheter ablation strategies vary among different centers. Seeking a simplified yet effective ablation approach will facilitate the application of catheter ablation in the treatment of vasovagal syncope. Purpose To evaluate the effectiveness and safety of anatomic ablation of the left superior ganglion plexus and right anterior ganglion plexus in the treatment of vasovagal syncope. Methods Patients with vasovagal syncope who tested positive on Head-up Tilt Testing were enrolled and divided into an ablation group and a control group. Patients in the ablation group underwent anatomic catheter ablation of the left superior ganglion plexus (LSGP) and right anterior ganglion plexus (RAGP) in addition to routine treatment, while patients in the control group received guideline-directed routine treatment. The primary endpoint was the occurrence of syncope and prodromal symptoms within 12 months. Results According to the inclusion and exclusion criteria, sixty-four patients were enrolled for analysis using propensity score matching with thirty-two in each group (ablation and non-ablationl) in the retrospective case-control study. The mean follow-up duration was 16.2±6.4 months. During the follow-up, 20.3% (13/64) of patients experienced syncope, and 32.8% (21/64) had prodromal symptoms. The incidence of syncope was lower in the ablation group compared to the control group (6.3% vs 34.4%, P=0.005). The incidence of prodromal symptoms was also lower in the ablation group compared to the control group (12.5% vs 53.1%, P&amp;lt;0.001). The number of syncope events was lower in the ablation group than in the control group (4/32 vs 22/32, P=0.021), and the number of prodromal symptoms was also lower in the ablation group (7/32 vs 29/32, P=0.001). Only one patient in the ablation group developed a hematoma at the puncture site, and no other complications were observed. Conclusion Anatomic ablation of the left superior ganglion plexus and right anterior ganglion plexus can reduce the occurrence of vasovagal syncope with high safety.A patient's ablation case 12 months follow-up results

IntroductionThere has been limited reports about the comorbid premature ventricular contractions (PVCs) and vasovagal syncope (VVS). Deceleration capacity (DC) was demonstrated to be a quantitative evaluation to assess the cardiac vagal activity. This study sought to report the impact of autonomic modulation on symptomatic PVCs in VVS patients.Methods and ResultsTwenty-six VVS patients with symptomatic idiopathic PVCs were consecutively enrolled. Identification and catheter ablation of left atrial ganglionated plexi (GP) and PVCs were performed in 26 and 20 patients, respectively. Holter 24 h-electrocardiograms were performed before and after the procedure to evaluate DC and PVCs occurrence. Eighteen patients were subtyped as DC-dependent PVCs (D-PVCs) and eight as DC-independent PVCs groups (I-PVCs). In D-PVCs group, circadian rhythm of hourly PVCs was positively correlated with hourly DC (P < 0.05) while there was no correlation in I-PVCs group (P > 0.05). Fifty-three GPs with positive vagal response were successfully elicited (2.0 ± 0.8 per patient). PVCs failed to occur spontaneously nor to be induced in six patients. In the remaining 20 patients, PVCs foci identified were all located in the ventricular outflow tract region. Post-ablation DC decreased significantly from baseline (P < 0.05). During mean follow-up of 10.64 ± 6.84 months, syncope recurred in one patient and PVCs recurred in another. PVCs burden of the six patients in whom neither catheter ablation nor antiarrhythmic drugs were applied demonstrated a significant decrease during follow-up (P = 0.037).ConclusionAutonomic activities were involved in the occurrence of symptomatic idiopathic PVCs in some VVS patients. D-PVCs might be facilitated by increased vagal activities. Catheter ablation of GP and PVCs foci may be an effective, safe treatment in patients with concomitant VVS and idiopathic PVCs.

Ganglionated plexi (GP) ablation may be associated with improved syncope or arrhythmia-free survival arrhythmia patients with vasovagal syncope (VVS) and atrial fibrillation (AF), respectively. We aimed to compare the characteristics of vagal response (VR) and clarify the effect on heart rate after GP ablation based on clinical diagnosis. A total of 83 consecutive patients undergoing GP ablation were divided following two groups: (1) GP ablation for VVS (VVS group, n = 43) and (2) GP ablation in addition to pulmonary vein isolation (AF group, n = 40). We examined VR characteristics during RF ablation and high frequency stimulation, respectively, in the VVS and AF groups. To evaluate immediate and long-term heart rate response, a standard 12-lead ECG was obtained at baseline at 24h after ablation and at the last follow-up visit. In the VVS group, the superior and inferior left atrial GPs were the most common GP sites at which a VR was observed. No VR was seen during radiofrequency application in the superior and inferior right atrial GPs in the VVS group. On the contrary, VR was more prevalent in the right-sided GPs during high-frequency stimulation in the AF group. VR was observed during ablation in only one patient with AF. Although the heart rate increased significantly after ablation in both groups, the effect was more prominent and durable in the VVS group. The autonomic response during GP ablation is different in VVS compared to AF, suggesting that VVS and AF may represent distinct forms of autonomic hyperactivity.

Cardioneuroablation is increasingly being adopted as a treatment for vasovagal syncope (VVS). Identification of the cardiac ganglionated plexus (GP) is a critical factor influencing the outcome of the procedure. This study sought to compare the efficacy of tentative anatomical ablation (TAA) and high-frequency electrical stimulation (HFS) in locating the GP. A total of 58 patients diagnosed with VVS were consecutively enrolled, including 46 patients with the cardioinhibitory type and 12 patients with the mixed type who exhibited a significant decrease in heart rate (HR). The first 19 enrolled patients simultaneously underwent HFS- and TAA-guided GP localization. All patients underwent anatomical GP ablation. The number of GP sites with a positive response to TAA was significantly greater than those from HFS (15 ± 4 per person vs. 12 ± 4 per person; p < 0.001). Following anatomical ablation, the patients exhibited an increase in HR (69 ± 13bpm vs. 91 ± 13bpm, p < 0.001), a reduction in sinus node recovery time (1155 ± 169 ms vs. 934 ± 162 ms, p < 0.001), an enhancement of atrioventricular conduction (Wenckebach point: 418 ± 87 ms vs. 338 ± 41 ms; effective refractory period of atrioventricular node: 334 ± 84 ms vs. 254 ± 54 ms, all p < 0.001), and a reduction in heart rate variability (HRV) (HRVSDNN: 146 ± 64 ms vs. 67 ± 29 ms; high frequency: 309.18 ± 99.42 vs. 24.21 ± 12.73, all p < 0.001). During a median follow-up of 18 months, the rate of freedom from syncope recurrent was 94.8%, with no statistically significant differences observed in age, gender, or type of head-up tilt test. In GP localization, TAA-guided responses demonstrated greater precision and wider distribution compared to HFS-guided approaches. Anatomical GP ablation can significantly decrease autonomic tone and prevent syncope in patients with VVS. Not applicable.

Advantages and pitfalls of selective cardioneuroablation targeting the atrioventricular node

Hybrid ablation [thoracoscopic ablation (TA) of atrial fibrillation (AF) followed by catheter ablation (CA)] is an increasingly common method of the treatment for patients with AF. The aim of this study was to assess the response to ganglionated plexi (GP) ablation in patients with a previous TA (i.e., to assess whether TA had resulted in damage to the GP. Heart rate variability (HRV) was used as a marker of the autonomic response. Twenty AF patients underwent pulmonary vein isolation (PVI) plus GP ablation (GP group) and 18 AF patients underwent CA including GP ablation as a part of hybrid ablation (i.e., all patients had undergone a previous TA; Hybrid group). In each group, a 5 min electrocardiogram (ECG) obtained before and after the CA were analyzed. Time and frequency domain parameters were evaluated. Vagal responses (VR) during CA were observed in 12 (60%) patients in the GP group; however, in the Hybrid group, VR was not observed in any of the patients during CA. The change in normalized power in the low frequency (LF) component and the ratio between the LF and high frequency (LF/HF ratio) components of the HRV spectra, before and after ablation, were statistically significant in the GP group (3.3±2.6 before vs. 1.8±1.9 after ablation) but unchanged, before or after CA, in the Hybrid group. GP ablation in patients subsequent to TA has a little influence on HRV parameters, which could be explained by GP damage during the preceding TA.

Left Atrial Ganglion Ablation as an Adjunct to Atrial Fibrillation Surgery in Valvular Heart Disease

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.

Cardioneuroablation for swallowing-induced syncope: To pace or to ablate, that is the question