Permanent Pacemaker Implantation or Cardioneuroablation in Sinus Node Dysfunction

This is a noncommercial, physician-initiated, monitored, multicenter, prospective randomized clinical trial, a proof-of-concept study, investigating a treatment strategy only. The study will use medical products applied for invasive and nonivasive procedures performed at the participating centers.

All patients meeting the inclusion criteria and not meeting the exclusion criteria will be invited to participate in the study. The patient will receive an informed consent form describing the study protocol. After speaking to the investigator and receiving detailed answers to all questions, the patient will sign the written informed consent form to participate in the study or will choose to opt out of randomization and to be included in the registry only.

Premenopausal women who will provide consent to participate in the study will undergo a pregnancy test before any invasive procedure. During the 12-month study duration, the use of effective contraception is recommended.

The patient will be asked to complete the questionnaires on bradycardia symptoms and quality of life (QOL).

Any patient included in the study will be randomized into group A or group B. Patients included in the registry (group C) will undergo patient-tailored interventions and treatments through shared decision-making with a possibility of permanent cardiac pacing (subgroup CA), vagal nerve stimulation (VNS) according to the protocol and cardioneuroablation (subgroup CB), as well as observation (subgroup CO).

Eligibility Criteria:
Inclusion Criteria:

* Age, 18-75 years
* Sinus node dysfunction/disease fulfilling criteria for elective pacemaker implantation according to current ESC guidelines (I, IIa, and IIb )
* Optimization of chronic disease treatment
* Ability to provide informed consent to participate in the study
* Ability to understand patient information.

Exclusion Criteria:

* Contraindications to invasive and noninvasive procedures used in the study
* Uncontrolled endocrine and systemic disorders
* Persistent atrial fibrillation
* Dilated cardiomyopathy
* Severe congenital heart valve disease or cardiomyopathy
* Functional NYHA class III/IV
* Left ventricular ejection fraction \<35%
* Left atrial diameter \>50 mm
* Previous catheter ablation
* Contraindications to anticoagulant treatment
* Contraindications to catheter ablation
* Chronic, advanced two- or third-degree atrioventricular block associated with structural heart disease
* Contraindications to noninvasive tests
* Pregnancy and lactation
* Previous cardiac surgery
* Implanted pacemaker device
* Neck and chest abnormalities
* Myocardial infarction in the previous 6 months
* Percutaneous coronary intervention in the previous 3 months
* Estimated survival \<24 months
* Participation in another drug or medical device program
* Limited capacity to understand the study protocol or psychological disorders precluding informed consent to participate in the study.
* Any other uncontrolled chronic diseases, neck and chest abnormalities, or disorders that constitute a contraindication to catheter ablation, antiarrhytmic treatment, general anesthesia, or extracardiac vagal nerve stimulation (ECANS)
* Severe obesity (body mass index ≥40 kg/m2 )