Unifocal Right-Sided Ablation Treatment for Neurally Mediated Syncope and Functional Sinus Node Dysfunction Under Computed Tomographic Guidance

Abstract

Background Biatrial, extensive, and complex ablation strategies have been published for the treatment of neurally mediated syncope, sinus node dysfunction, and functional atrioventricular block. We have developed a less extensive and more specific approach compared with previously published cardioneuroablation strategies, called cardio-neuromodulation. It is based on tailored vagolysis of the sinoatrial node through partial ablation of the anterior right-ganglionated plexus, preferentially through a right-sided approach. Methods Patients with syncope were enrolled between December 2016 and December 2017. They were assigned to group A if they had a positive head-up tilt test and to group B if they presented with a pause ≥3 seconds. The area to target during cardio-neuromodulation was designed offline on a computed tomographic scan. Slow heart rates and pauses were compared during 24-hour rhythm registration at baseline, at 1-month follow-up, and 6-month follow-up. Syncope burden was assessed before the procedure and at 3- and 6-month follow-up. Results Twenty patients underwent cardio-neuromodulation through a right-sided approach (12 in group A, 8 in group B). The first application of radiofrequency energy led to a P-P interval shortening >120 ms in all 20 patients. After a mean±SD ablation time of 7±4 minutes and mean ablated surface area of 11±6 mm 2 , the P-P interval shortened by 219±160 ms ( P <0.001). The number of beats <50/min during 24-hour rhythm registration was reduced by a median of 100% at 6-month follow-up ( P <0.001). Syncope burden was reduced by 95% at 6-month follow-up ( P <0.001). Conclusions These data indicate that cardio-neuromodulation, through a right-sided and computed tomographic–guided procedure, is safe, fast, and highly reproducible in preventing inappropriate functional sinus bradycardia and syncope recurrence.

Long-term Efficacy and Safety of Cardioneuroablation in Patients with Vagally Mediated Bradyarrhythmias

“…Long-term efficacy of CNA in SND and AVB has been studied less than VVS (5,7,11,12) . In a recently published trial, Debruyne et al (12) studied the potential role of restricted right atrial approach in patients with SND and VVS and demonstrated a similar efficacy. However, short-term effects were presented in this study.…”

Letter by Debruyne regarding article “Selective ablation of atrial ganglionated plexus attenuates vasovagal reflex in a canine model”

“…In our institution, we perform cardio‐neuromodulation (CardNM)—defined as a tailored vagolysis of the sinus node by targeting the ARGP plexus endocardially to prevent cardioinhibitory syncope and neurally mediated syncope (NMS) of the mixed type. Four years ago, we first targeted the ARGP from the left endocardium, and have moved to a right‐sided approach during the last 3 years . Our group also showed that the ARGP belongs to the final common pathway of sinus node vagal innervation in humans …”

“…Four years ago, we first targeted the ARGP from the left endocardium, and have moved to a right‐sided approach during the last 3 years . Our group also showed that the ARGP belongs to the final common pathway of sinus node vagal innervation in humans …”

“…We have shown that it is possible to prevent NMS, functional sinus bradycardia, and vagally mediated atrioventricular (AV) block by performing CardNM . Targeting solely the ARGP has an indirect influence on the AV conduction through the ARGP‐IRGP pathway.…”

“…We agree that in a limited subset of patients—who remain to be identified—that additionally targeting the IRGP could be of value for the prevention of AV‐block occurrence. While the ARGP is located a mean distance of 4 cm from the normal AV conduction, the IRGP is located close to the normal AV conduction . To avoid exposing patients to additional unnecessary risks, we believe that CardNM—via a right‐sided approach—should be the first step in all the patients with NMS who are referred for ablation.…”