1. Department of Cardiology, Sorlandet Hospital, Arendal, Norway
2. Department of Cardiology, Sorlandet Hospital, Kristiansand, Norway
3. Department of Primary Health Care Services, Aalesund Municipality, Aalesund, Norway
4. Department of Cardiology, Oslo University Hospital Ullevaal, Oslo, Norway
5. Institute of Clinical Medicine, University of Oslo, Oslo, Norway