Bradycardia; Syncope, Syncope, Vasovagal
Conditions
Keywords
Cardiac denervation, Cardio-inhibitory syncope
Brief summary
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.
Interventions
PROCEDUREElectrophysiological study
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.
PROCEDUREElectrophysiological study and Right side Ganglionated Plexi ablation
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.
PROCEDUREElectrophysiological study and bi-atrial Ganglionated Plexi ablation
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.
Sponsors
Abbott
University of Sao Paulo General Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
all patients will go for intervention, however they will not know which group they were randomized to
Intervention model description
randomized, prospective, sham controll, on a 1:1:1 basis to group A (Sham - 15 patients); group B (right sided denervation - 15 patients); and group C (bilateral denervation - 15 patients)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Aged between 18 and 70 years old. * Cardio-inhibitory response (VASIS 2A or 2B) during tilt test, or after carotid sinus massage. * Patients with bradycardia mediated by vagal hypertonia documented on 24-hour Holter monitoring and a clear relationship with symptoms.
Exclusion criteria
* Ages under 18 and over 70 * Presence of structural heart disease documented by echocardiography. * Hypothyroidism and hyperthyroidism, drug effects, obstructive sleep apnea and other causes of secondary bradycardia. * Anatomical disease of the conduction system.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| recurrence of syncope | 24 months | To compare the recurrence of syncope or pre-syncope and a negative tilt test with the different techniques of electrophysiological procedures currently used. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| electrocardiographic and electrophysiological parameters | 24 months | 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. |
Countries
Brazil
Contacts
Primary ContactMauricio I scanavacca, MD, PhD
Backup ContactEsteban W Rivarola, MD, PhD
Outcome results
None listed