1. Department of Cardiology, Hospital of Southern of Norway, 4604 Kristiansand, Norway
2. ProCardio, Center for Innovation, Department of Cardiology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
3. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0318 Oslo, Norway
4. Centre for Innovative Ultrasound Solutions and Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, 7491 Trondheim, Norway
5. Clinic of Cardiology, St Olavs Hospital, 7006 Trondheim, Norway