The purpose of this study is to evaluate the effectiveness of cardioneuroablation for the treatment of neurocardiogenic syncope (NCS), also known as "vaso-vagal" syncope. Syncope is a general term for passing out spells and neurocardiogenic syncope is a specific form of passing out spells caused by sudden drops in heart rate or blood pressure. Although the specific mechanisms of NCS are not well understood, it is believed that some people are prone to developing passing out spells in specific situations such as standing up for a long period of time, pain or nausea. In these situations, the body reacts with a paradoxical reflex which leads to a drop in blood pressure and heart rate and causes passing out. Certain types of medications are used to treat NCS including beta-blockers, midodrine and florinef, among others. However, none of these medications are particularly effective at preventing passing out spells and many people continue to have episodes despite trying different medications.

Cardioneuroablation is a new form of treatment for NCS. The term ablation means using a wire to make small electrical burns in the heart. Ablation has been used for many years to treat other electrical disturbances in the heart but the use of ablation to treat NCS is a new application. The goal of cardioneuroablation is to identify areas within the heart which are believed to initiate the reflex which triggers the drop in heart rate and blood pressure that leads to passing out. In preliminary studies, it has been suggested that cardioneuroablation may be significantly more effective than medications at preventing passing out spells for people with NCS.

Hypothesis: Cardioneuroablation of vagal inputs in the left atrium may serve as an effective treatment modality for the prevention of NCS by blunting the initial trigger of the cascade that leads to symptoms and syncope.

Inclusion Criteria:

• Subject is able and willing to sign and date the Patient Consent Form
• Subject is 18 years of age or older
• Subject is expected to remain available for the follow-up protocol
• Subject is willing to comply with the follow-up procedures
• Subject has medically documented history of neurocardiogenic syncope
• Subject has had 3 episodes of syncope or presyncope in last 12 months
• Subject has had a positive tilt table test, defined as the presence of syncope or presyncope associated with abrupt hypotension (SBP < 70 mmHg) or bradycardia (HR < 40 bpm), with or without sublingual nitroglycerin provocation or atropine challenge
• Subject has been tried on at least one pharmacologic therapy for at least 4 weeks

Exclusion Criteria:

• Subject has signs and symptoms of an active infection (i.e. fever, elevated white blood cell count, etc.) which has not been treated and/or has not demonstrated improvement in white blood cell count and resolution of fever
• Subject is pregnant or planning to become pregnant within the study protocol follow-up
• Subject is enrolled or planning to participate in a concurrent drug and/or device study during the course of this study that would confound study results as determined by the study physician
• Subject is unwillingly to comply with the randomization procedure
• Subject has had no syncopal episodes in last six months while on medical therapy
• Subject has one of the following conditions that is the documented source of syncope: sick sinus syndrome, sinus node or atrioventricular conduction deficiencies, ventricular tachyarrhythmias, pulmonary hypertension, hypertrophic cardiomyopathy, history of transient ischemic attack, seizure disorders, subclavian steal syndrome, or drug-induced syncope
• Subjects with a myocardial infarction within last six months
• Subjects with severe heart failure (NYHA class III or IV), previous heart surgery, structural heart disease, or an infiltrative cardiac disease
• Subject is contraindicated for left-atrial ablation, as determined by enrolling physician

No due to limited data set and study ending.

Data for adverse events were collected for 12 months.