1 Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
2 Clinic of Cardiology, St Olav's University Hospital, Trondheim, Norway.
3 Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
4 Clinic of Cardio-Thoracic Surgery, St Olav's University Hospital, Trondheim, Norway.