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 mm², 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.

Trial registration: ClinicalTrials.gov NCT02954666.

Keywords: atrioventricular block; autonomic nervous system; bradycardia; denervation; follow-up studies; syncope.