A randomized, single-blind study comparing two pacing strategies in patients with atrioventricular block requiring permanent pacemaker implantation. This trial evaluates the impact of conduction system pacing (left bundle branch area pacing) versus standard right ventricular pacing on central hemodynamics, cardiac function, and patient quality of life over 12 months. The study will enroll 124 patients from two Estonian tertiary hospitals and measure central systolic arterial pressure as the primary outcome, with secondary assessments of arterial stiffness, echocardiographic parameters, electrical activation patterns, and quality of life scores.

Inclusion Criteria:

• Age 18-80 years
• Diagnosis of atrioventricular block
• Expected survival >1 year

Exclusion Criteria:

• Reduced left ventricular ejection fraction (EF <45%)
• Expected ventricular pacing burden <20%
• Inter-arm systolic blood pressure difference >15 mmHg
• Percutaneous coronary intervention or coronary artery bypass surgery within the last 30 days
• Secondary hypertension
• Orthostatic hypotension
• Clinically significant valvular heart disease
• Congenital heart disease
• Pulse wave analysis or pulse wave velocity measurement cannot be reliably performed
• Pregnancy or breastfeeding
• Withdrawal of consent by the subject
• Loss of contact during the study