This is a prospective, non-interventional cohort study. It tests the hypothesis that

• Pacemaker-derived monitoring of sleep-related breathing disorders and/or daily physical activity predicts clinical outcome.
• Autonomic imbalance defined by an increased periodic repolarisation dynamics (PRD) predicts clinical outcome in pacemaker patients.
• Autonomic imbalance defined by an increased periodic repolarisation dynamics (PRD) predicts the occurrence of device-detected atrial fibrillation and/or device-detected sleep apnea.
• Enviromental factors such as ambient temperature, humidity, precipitation, air pressure impacts device-detected atrial fibrillation and/or device-detected sleep apnea.
• Variation of night-to-night device-detected sleep apnea shows sex-specific patterns and impacts device-detected atrial fibrillation burden, ventricular pacing rate in sick sinus syndrome and clinical outcomes.
• Burden / variation of device-detected sleep apnea and/or device-detected atrial fibrillation correlates with the incidence and severity of common ophthalmologic diseases.

All forms of arrhythmias, sleep apnea during sleeping hours and physical activity using sensors in modern implanted pacemakers as well as autonomic imbalance measures will be correlated with the incidence and progression (within 5 years of follow-up) of common co-morbidities such as arterial hypertension, coronary artery disease, heart failure, COPD, peripheral artery disease, iron insufficiency. In a long follow up perspective major adverse cardiovascular events will be recorded and new risk scores will be developed, incorporating machine learning techniques.

Inclusion Criteria:

• implanted Microport TEO SR/DR or BOREA SR/DR or ALIZEA SR/DR pacemaker device
• signed informed consent

Exclusion Criteria:

• any contraindication to perform a cardiac CT examination
• eGFR < 30 ml/min/1.73 m2
• allergy against CT contrast medium
• hyperthyreoism
• inability of the patient to understand the study purpose and plan
• inability of the patient to perform baseline examinations
• pregnancy or breast-feeding; women with childbearing potential
• estimated life expectancy below one year

Patients with pacemakers are usually above the age of 65 years, and suffer from common co-morbidities such as arterial hypertension, coronary artery disease, heart failure, COPD, peripheral artery disease, iron insufficiency, sleep disordered breathing, obesity and/or physical inactivity / de-conditioning.