This is a multicenter prospective randomized blind controlled trial with a sham procedure group of the efficacy and safety of cardioneuroablation as a method of treating symptomatic bradycardia without a permanent pacemaker implantation

Catheter ablation is a common treatment for cardiac arrhythmias. Some patients with AF ablation or AVNRT experience acceleration of sinus rhythm, the most likely cause of which is modification of autonomic tone caused by inadvertent damage to intramural autonomic ganglia and fibers. Intentional damage to these plexuses has become known as cardioneuroablation (CNA) and is currently used in patients with tachycardia-bradycardia syndrome, vegetatively caused sinus node dysfunction and atrioventricular conduction disorders, vasovagal syncopal conditions developing in a cardioinhibitory type.

It is suggested that in some patients CNA may become an alternative to permanent pacemaker for the treatment of symptomatic bradyarrhythmias.

This is a multicentre randomised clinical study evaluating the efficacy of cardioneuroablation for severe bradycardia due to sinus node dysfunction and/or atrioventricular nide dysfunction versus a sham procedure.

Inclusion Criteria:

1. Any of the following variants of bradyarrhythmia in patients aged 18-65 years:

   (1.1.) Symptomatic sinus bradycardia or bradycardia due to atrioventricular blockade, including transient.

   (1.2.) Severe asymptomatic sinus bradycardia with a rhythm frequency of <30 beats/min.

   (1.3.) Transient atrioventricular block of II-III degree or permanent block of II degree.

   (1.4.) Repeated fainting or pre-fainting states with a proven association with bradycardia (without injury).

   (1.5.) Rhythm pauses >6 seconds.

   In combination with the following two criteria:

2. Positive reaction to physical activity and/or atropine test:

   (2.1.) Increase in sinus rhythm frequency ≥25% or >90 beats/min. (2.2.) The transition of atrioventricular blockade of the II-III degree to the 1st degree or complete normalization of atrioventricular conduction at the sinus rhythm.

3. Sinus rhythm at the time of switching on

Exclusion Criteria:

1. Anamnesis of injury during syncopation due to bradycardia, except in the case when the patient refused to implant an electrocardiostimulator for his own reasons in writing;
2. Constant intake of antiarrhythmic drugs (for PVC, AF, etc.);
3. The presence of an implanted pacemaker, a heart contractility modulation device, a cardioverter defibrillator;
4. Drug-induced sinus bradycardia and/or atrioventricular block;
5. Bradycardia due to electrolyte imbalance (e.g. hyperkalemia);
6. Bradycardia due to hypothyroidism or other reversible conditions;
7. No reaction to the administration of atropine (up to a maximum dose of 0.2 mg / kg);
8. Proven association of bradyarrhythmia with episodes of apnea/hypopnea in obstructive sleep apnea syndrome;
9. Clinically significant coronary artery disease;
10. Postinfarction cardiosclerosis;
11. Hemodynamically significant congenital heart defects, including operated ones;
12. Stroke or transient ischemic attack <3 months;
13. Open heart surgery in the anamnesis;
14. Catheter interventions on coronary arteries or for cardiac arrhythmias <3 days;
15. Conditions after percutaneous coronary angioplasty <3 months;
16. Anamnesis of stable ventricular tachycardia on the background of bradycardia;
17. Pregnancy or breastfeeding period