1. Department of Cardiology, Karolinska University Hospital , Solna, S1:02, SE-17176 Stockholm , Sweden
2. Medical Department I (Cardiology, Angiology, Pneumology), Klinikum rechts der Isar , Technical University of Munich, Ismaninger Str. 22, DE-81675 Munich , Germany
3. Department of Clinical Sciences, Karolinska Institute, Arrhythmia Center Stockholm , South Hospital, Sjukhusbacken 10, SE-11883, Stockholm , Sweden
4. Department of Cardiology, Sahlgrenska University Hospital, Gothenburg , Blåa Stråket 3, 141345 Göteborg , Sweden
5. Thoracic Center, Blekinge County Hospital , Lasarettsvägen, SE-371 85, Karlskrona , Sweden
6. Department of Public Health and Clinical Medicine, Umeå University , SE-90187 Umeå , Sweden
7. Department of Cardiology, Linköping University Hospital , SE-581 85 Linköping , Sweden
8. Department of Cardiology, Skåne University Hospital Lund , SE-221 85 Lund , Sweden