Effect of general and local anesthesia on the vagal response characteristics during ganglionated plexus ablation

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.

We aimed to determine the effects of conscious and deep sedation on vagal response (VR) characteristics during ganglionated plexus (GP) ablation. Forty consecutive patients undergoing GP ablation for vasovagal syncope were divided to receive conscious sedation with midazolam (Group 1, n = 29) or deep sedation with the midazolam-propofol combination (Group 2, n = 11). VR was defined on three levels. R-R interval increase of >50% (Level 1); R-R interval increase of 20%-50% (Level 2); and R-R interval increase of <20% (Level 3). The ratio of Level 1 VR during ablation on left superior and inferior GPs was significantly lower in Group 2 (p < .0001 and p = .034, respectively). Once the cut-off for VR was decreased to Level 2, the ratio of (+) VR was similar between groups during ablation of left-sided GPs. Positive VR in any level was lower than 20% during ablation of right-sided GPs. The autonomic tone might be affected in different ways by the level or type of intravenous sedation. Awareness of anesthesia-related differences may be important if GP ablation will be performed by using VR characteristics during ablation.

AB-453070-1 NOVEL INSIGHTS OF GANGLIONATED PLEXI ABLATION FOR ATRIAL FIBRILLATION: FINDINGS FROM RECURRENCE CASES

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

BackgroundModulation of the cardiac autonomic nervous system (ANS) is a promising adjuvant therapy in the treatment of atrial fibrillation (AF). In pre-clinical models, pulsed field (PF) energy has the advantage of selectively ablating the epicardial ganglionated plexi (GP) that govern the ANS. This study aims to demonstrate the feasibility and safety of epicardial ablation of the GPs with PF during cardiac surgery with a primary efficacy outcome of prolongation of the atrial effective refractory period (AERP).MethodsIn a single-arm, prospective analysis, patients with or without a history of AF underwent epicardial GP ablation with PF during coronary artery bypass grafting (CABG). AERP was determined immediately pre- and post- GP ablation to assess cardiac ANS function. Holter monitors were performed to determine rhythm status and heart rate variability (HRV) at baseline and at 1-month post-procedure.ResultsOf 24 patients, 23 (96%) received the full ablation protocol. No device-related adverse effects were noted. GP ablation resulted in a 20.7 ± 19.9% extension in AERP (P < 0.001). Post-operative AF was observed in 7 (29%) patients. Holter monitoring demonstrated an increase in mean heart rate (74.0 ± 8.7 vs. 80.6 ± 12.3, P = 0.01). There were no significant changes in HRV. There were no study-related complications.ConclusionsThis study demonstrates the safety and feasibility of epicardial ablation of the GP using PF to modulate the ANS during cardiac surgery. Large, randomized analyses are necessary to determine whether epicardial PF ablation can offer a meaningful impact on the cardiac ANS and reduce AF.Trial registrationClinical trial registration: NCT04775264.

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

Vagal responses during cardioneuroablation on different ganglionated plexi: Is there any role of ablation strategy?

Cardiac autonomic ganglia ablation suppresses atrial fibrillation in a canine model of acute intermittent hypoxia.

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

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.

Additional Ganglion Plexus Ablation During Thoracoscopic Surgical Ablation of Advanced Atrial Fibrillation: Intermediate Follow-Up of the AFACT Study.

CSPE Young Investigator Award Session

Ganglion Plexus Ablation in Advanced Atrial Fibrillation: The AFACT Study

AF termination was often occurred during ganglionated plexi (GP) ablation. The purpose of this study was to characterize the electrograms at the site of AF termination by GP ablation. Method: Eighteen patients with AF termination by GP ablation were studied. In case of patients with sinus rhythm, AF was induced by rapid atrial pacing. The sites where vagal response was evoked by high-frequency stimulation were determined as GP sites and ablated. The bipolar electrograms were recorded in a 4.5-s window before the RF delivery. Result: AF termination was seen at superior left GP ablation in 3 patients, anterior right in 2 patients, inferior left in 6 patients, and inferior right (in 7 patients). Continuous electrical activity (CEA) was seen at the termination site in 16 (89%) patients. Other 2 patients without CEA, cycle length was 207±18 ms. The maximum duration of CEA was 1.8±0.3 of 4.5 sec. There were 2 patients with only CEA at the termination sites during all recording period. The maximum amplitude of CEA in 16 patients was 0.58±0.99 mV. Conclusion: The electrograms at the sites of AF termination by GP ablation show mainly transient CEA with relatively low voltage.

Advantages and pitfalls of selective cardioneuroablation targeting the atrioventricular node