1. Department of Cardiology, Institute for Surgical Research and Centre for Cardiological Innovation Oslo University Hospital Rikshospitalet, PO Box 4950 Nydalen N–0424 Oslo Norway
2. University of Oslo Norway
3. Arrhythmia Clinic Skåne University Hospital and Department of Cardiology, Clinical Sciences, Lund University Lund Sweden
4. Department of Radiology and Nuclear Medicine Oslo University Hospital, Rikshospitalet and University of Oslo Norway
5. Department of Cardiology Rigshospitalet Copenhagen University Hospital Copenhagen Denmark