Endocardial Autonomic Denervation of the Left Atrium to Treat Vasovagal Syncope

Abstract

Background— Vasovagal syncope (VVS) is the most common cause of recurrent syncope that can be debilitating despite optimal conventional therapy. The aim of this study was to evaluate the feasibility and efficacy of selective endocardial autonomic denervation in left atrium (LA) as an alternative treatment strategy in patients with highly symptomatic VVS. Methods and Results— Ten consecutive patients (mean age, 50.4±6.4 years; 7 women) with a medium of 3.5 (range, 2–20) recurrent episodes of VVS during the preceding year and positive head-up tilt testing in whom standard therapies were ineffective or poorly tolerated were enrolled. Ganglionated plexi (GP) in the LA, identified by high-frequency stimulation, was targeted by radiofrequency catheter ablation. The patients were then followed up at 3, 6, 12, 24, and 36 months, including repeated head-up tilt testing and Holter at 3 and 12 months. Radiofrequency energy was applied at the left superior GP in 10 patients, right anterior GP in 5, and left inferior GP in 3, using an 8-mm ablation catheter. Vagal response, defined as transient ventricular asystole, atrioventricular block, or an increase in R-R interval by 50%, was observed during ablation in all GP sites. The end point of procedure was the inhibition of the vagal response at target sites. At 30±16 (range, 13–55) months of follow-up, no patient had any recurrence of syncope and all patients had significant improvement in symptoms, but 5 of 10 patients reported transient prodromes. No complications occurred. Conclusions— Comprehensive endocardial autonomic denervation of the LA demonstrates the feasibility of treating VVS in medium-term follow-up.