1. Department of Cardiology, Odense University Hospital, J. B. Winsløws Vej 4, Odense, Denmark
2. Department of Heart, Lung and Vascular Surgery, Odense University Hospital, J. B. Winsløws Vej 4, Odense, Denmark
3. Danish Pacemaker and ICD Register, Department of Cardiology, Odense University Hospital, J. B. Winsløws Vej 4, Odense, Denmark
4. Department of Cardiology, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, Aarhus, Denmark
5. Department of Cardiology, Aalborg University Hospital, Hobrovej 18-22, Aalborg, Denmark
6. Department of Cardiology, Blegdamsvej 9, Denmark, Rigshospitalet, Copenhagen