Patients entering the study will attend for implantation of a pacemaker device and be randomised to either right ventricular pacing or physiological pacing.
The PROTECT-HF multi-centre randomised controlled trial will compare two different pacing approaches for treating patients with slow heart rates. In it the investigators will compare a long-standing standard approach for pacing; right ventricular pacing, with a new form of pacing, physiological pacing (His and Left bundle area pacing) in 2600 patients.~Patients will be allocated at random to receive either right ventricular pacing or physiological pacing. Endpoint measurements will be undertaken at baseline, and at six-monthly intervals post-randomisation. Treatment allocation will be blinded to the endpoint assessor and the patient.~Recruitment and pacemaker implantation will be carried out at each participating centre. The primary analysis will be intention to treat. The investigators will also perform an on-treatment analysis.~2048 patients are needed to detect the expected effect size with 85% power. A total of 2600 patients will be recruited to allow for patient drop-out and crossover.