Extracardiac Vagal Stimulation-Assisted Cardioneuroablation: Dynamically Evaluating the Impact of Sequential Ganglionated Plexus Ablation on Vagal Control of SAN and AVN in Patients with Sinoatrial Node Dysfunction

Abstract

Cardioneuroablation (CNA) is proposed as a promising therapy for patients with sinoatrial node dysfunction (SND) that is mediated by excessive vagal tone. However, a series of urgent questions about CNA remain unanswered. From December 2020 to March 2022, six patients with symptomatic SND who underwent CNA were summarized in this report. Sequential CNA targeting Ao-SVC GP, PMLGP, RAGP, and LSGP was performed in patients, guided by fractionated intracardiac electrograms and dynamically evaluated by extracardiac vagal stimulation (ECVS). The results showed that Ao-SVC GP ablation led to a significant increase in heart rate (HR) and the elimination of sinus arrest evoked by ECVS, while the vagal responses of atrial ventricular block were eliminated by the ablation of PMLGP and LSGP. Post-procedure HR increased up to 64–86% of the maximum HR of an atropine test at baseline. The median HR from Holter monitoring increased from 52.8 ± 2.1 bpm at baseline to 73.0 ± 10.4 bpm after the procedure (p = 0.012) and to 71.3 ± 10.1 bpm at the six-month follow-up (p = 0.011). Bradycardia-related symptoms disappeared in all patients at the six-month follow-up. This case series reveals the feasibility of using the ECVS-assisted sequential CNA technique and indicates the critical role of ECVS in dynamically evaluating the impact of sequential CNA on the vagal control of SAN and AVN.

Cardioneuroablation for successful treatment of symptomatic bradycardia in a 12-year-old child after a 6-month follow-up

“…The cell bodies of cardiac efferent vagal postganglionic neurons have been shown to be contained in the intrinsic cardiac GP, which is embedded in the atrial wall and in epicardial fat pads ( 10 , 11 ). Common GPs include Ao-SVC GP, PMLGP, RAGP, RIGP, LSGP, and LIGP with different physiological functions, and they interact with one another ( 6 , 9 , 10 ). Therefore, a disruption of nerve fibers by radiofrequency ablation can inhibit excessive activation of the vagal nerve, thereby eliminating or improving clinical symptoms.…”

Selection of patients with symptomatic vagal-induced sinus node dysfunction: Who will be the best candidate for cardioneuroablation?

“…Most efferent cardiac vagal fibers to the atrium, sinus node, and atrioventricular node pass through this area and then project onto the RAGP (Armour et al, 1997;Chiou et al, 1997). A recent study confirmed that the ablation of SVC-Ao GP significantly increased the heart rate, while elimination of vagal response evoked by extracardiac vagal stimulation (Chen et al, 2022). The RAGP and SVC-Ao GP were considered more valuable candidate targets to modulate sinus node function in symptomatic SND patients when compared with other GPs.…”

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

“…In clinical practice, the reproduction of cardioinhibition is achieved through the HUTT, and in the laboratory, the sole method capable of replicating a similar controlled condition is ECVS. 10,19,23 Both in spontaneous events and during the HUTT, there is a massive vagal response simultaneously affecting all regions with vagal innervation, particularly the sinus node, AV node, and atrial walls. This condition can be readily reproduced with ECVS as many times as necessary, depending on the operator, as illustrated in Figure 2A,B.…”

“…Furthermore, cardioinhibition typically involves a substantial bilateral vagal response, and the control method must replicate it as closely as possible. In clinical practice, the reproduction of cardioinhibition is achieved through the HUTT, and in the laboratory, the sole method capable of replicating a similar controlled condition is ECVS 10,19,23 . Both in spontaneous events and during the HUTT, there is a massive vagal response simultaneously affecting all regions with vagal innervation, particularly the sinus node, AV node, and atrial walls.…”