PO-02-232 CARDIONEURAL ABLATION IN THE MANAGEMENT OF LONG QT SYNDROME, TYPE 7

Abstract

Vasovagal syncope is a complex interaction of neurologic and cardiovascular mechanisms resulting in cardiac inhibition by the parasympathetic nervous system via the vagus nerve and associated ganglionic plexi. Some types of tachycardia may be induced by bradycardia, LQT type 3 being the most common example. In these patients, a pacemaker is sometimes indicated to avoid the bradycardia trigger for tachycardia. Cardioneural ablation (CNA) is an emerging therapy that offers the potential of abolishing vagal-induced bradycardia. It is most commonly used to treat vasovagal syncope but it may also provide benefit to patients with bradycardia-induced tachyarrhythmias. We present a case of a patient with Long QT type 7 with vasovagal syncope who had an asystolic pause which induced a run of nonsustained VT. Cardioneural ablation was utilized to avoid bradycardia, with the intention of avoiding future triggering of VT. An 8-year-old female with a past-medical history of Andersen-Tawil Syndrome (Long QT Syndrome type 7). She had two syncopal events which suggested a vagal etiology. After loop monitor placement, she had a third syncopal event, which recorded a period of sinus bradycardia, culminating in a 6.3 second asystolic pause, followed by a 6 beat run of VT, with cycle length of 200-260 msec. Cardioneural ablation was considered as a means of avoiding future bradycardic events. Procedure was performed under general anesthesia. Electroanatomic mapping (Ensite Precision) was used to create 3D cardiac geometry. The same system, coupled with transthoracic ultrasound, was also used to guide transseptal puncture. Sinus bradycardia could be induced at baseline with vagal stimulation. Areas of fractionated signals were mapped to the high atrial septum between the right upper pulmonary vein and the fossa ovalis; and also in the roof of the coronary sinus. Patient was known to have a persistent left SVC to the coronary sinus. These areas were targeted for ablation. Post ablation, she had no bradycardia inducible with vagal stimulation. She tolerated the procedure well, without complication. CNA shows potential promise in the treatment of vasovagal syncope. However, there may be other clinical settings in which it finds utility. Conditions which might benefit include Andersen-Tawil syndrome, Long QT type 3, Brugada syndrome, and possibly Congenital Central Hypoventilation syndrome. Further investigation is needed to elucidate the safety and efficacy of CNA in these settings.