1. Department of Cardiology; Sørlandet Hospital; Arendal Norway
2. Institute of Clinical Medicine, University of Oslo; Oslo Norway
3. Department of Global Public Health and Primary Care; University of Bergen; Bergen Norway
4. Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital; Bergen Norway
5. Division of Epidemiology; Norwegian Institute of Public Health; Bergen Norway
6. Research Department; Sørlandet Hospital; Kristiansand Norway
7. Women's and Children's Department, Oslo University Hospital; Oslo Norway
8. Department of Cardiothoracic Surgery, Oslo University Hospital; Oslo Norway