Background: Autonomic system modification is an established therapeutic approach that has been increasingly used for the treatment of vagal-related symptomatic bradycardia, such as cardio-inhibitory vasovagal syncope1-12. Although convincing results had been reported from small populations, a large randomized study providing robust evidence on the efficacy of this approach has not yet been performed. Hypothesis: Cardiac autonomic system modification is effective for the treatment of vagal-related symptomatic bradycardia, and is associated better clinical results as compared to placebo.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
45
Electrophysiological study: patients in a fasting state and under total intravenous anesthesia Intracardiacelectrogramsare displayed simultaneously on a multichannel recorder. Programmed atrial and ventricular stimulation are performed to rule out sustained arrhythmias, primary conduction system dysfunction, and sick sinus syndrome.
Electrophysiological study: patients in a fasting state and under total intravenous anesthesia Intracardiacelectrogramsare displayed simultaneously on a multichannel recorder. Programmed atrial and ventricular stimulation are performed to rule out sustained arrhythmias, primary conduction system dysfunction, and sick sinus syndrome. GP Mapping and Cardiac denervation: Specific atrium sites are empirically identified as GP by presumed anatomic location based on previous works (anatomic mapping): In the RA: the posterior aspect of the interatrial septum, between the posterior wall and coronary sinus ostium; and, the septal aspect of the superior vena cava junction (opposite to the LA GP tags). A 3.5-mm irrigated tip catheter will be used to deliver radiofrequency energy (50°C, 20-30 W, for 30-60 seconds) with a 17 mL/min irrigation flow.
Electrophysiological study: patients in a fasting state and under total intravenous anesthesia Intracardiacelectrogramsare displayed simultaneously on a multichannel recorder. Programmed atrial and ventricular stimulation are performed to rule out sustained arrhythmias, primary conduction system dysfunction, and sick sinus syndrome. GP Mapping and Cardiac denervation: Specific atrium sites are empirically identified as GP by presumed anatomic location based on previous works(anatomic mapping): In the LA: the inferior right GP (septal aspect of the right pulmonary veins \[PV\]) antra, and LA posterior wall. In the RA: the posterior aspect of the interatrial septum, between the posterior wall and coronary sinus ostium; and the septal aspect of the superior vena cava junction (opposite to the LA GP tags). A 3.5-mm irrigated tip catheter will be used to deliver radiofrequency energy (50°C, 20-30 W, for 30-60 seconds) with a 17 mL/min irrigation flow.
University of Sao Paulo General Hospital
São Paulo, São Paulo, Brazil
Arrhythmia and electrophysiology of the Heart Institute - University of São Paulo
São Paulo, Brazil
recurrence of syncope
To compare the recurrence of syncope or pre-syncope and a negative tilt test with the different techniques of electrophysiological procedures currently used.
Time frame: 24 months
electrocardiographic and electrophysiological parameters
Compare the following electrocardiographic and electrophysiological parameters of vagal attenuation: * Heart rate (bpm - beats per minute); * Internal AH (represents AV internodal conduction time, with normal values between 50-120 ms); * Wenckebach cycle; * Presence of Holter pauses 30 days after the intervention.
Time frame: 24 months
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