The purpose of this study is to evaluate the quality of life, patient acceptance and exercise capacity with leadless compared to transvenous pacing in elderly patients with new-onset high-grade atrioventricular block. Consecutive patients with high-grade atrioventricular black and preserved sinus node function with indication for permanent pacemaker implantation according to the latest european guidelines, are included in a prospective, partly patient and accessor blinded and partly open label, 1:1 randomized combined parallel and cross-over trial to implantation with 1) a Micra AV Transcathter Pacing System or 2) an Azure XT DR dual chamber pacemaker.

Inclusion Criteria:

• First time pacemaker implantation on class I or II ESC recommendations for AVB with an expected amount of right ventricular pacing >80% of the time,
• Age 75 years or older
• Intact sinus node function
• Expected survival more than 12 months based on clinical evaluation
• Able to provide informed consent

Exclusion criteria:

• Persistent or previous cardiac implantable electronic device i.e., pacemaker, ICD, or CRT.
• Persistent, or chronic atrial fibrillation
• Reversible AVB
• Transient AVB due to ongoing ischemia
• Heart failure NYHA class III-IV
• Heart failure with branch block and indication for CRT implantation, irrespective of NYHA class
• Indication for primary or secondary prophylactic ICD implantation
• Acute myocardial infarction (AMI) within 3 months
• Severe chronic pulmonary disease with pulmonal hypertension limiting exercise capacity
• Expected survival < 12 months based on clinical evaluation
• Performing high intensity sport
• Participation in another trial with experimental treatment
• Contraindication against device implantation (e.g., concurrent infection)
• Failure to provide informed consent

In accordance with Danish and European data protection law

Partly patient and accessor blinded and partly open label.