1. Department of Heart Disease, Haukeland University Hospital, N-5021 Bergen, Norway
2. Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
3. Second Cardiology Department, Attikon University Hospital, University of Athens, Athens, Greece
4. Hôpital Cardiologique du Haut Lévêque Université Victor Segalen Bordeaux II, Bordeaux, 33604 Pessac, France
5. Service de Cardiologie, Faculté de Médecine, Centre Hospitalier Universitaire Trousseau, Université François Rabelais, Tours 37044, France
6. Second Cardiology Department, University Hospital of Pisa, Pisa, Italy
7. Arrhythmia Department, University Hospital, 38043 Grenoble, France
8. Cardiology Department, Ramon y Cajal Hospital, Alcalá University, Carretera Colmenar Viejo, 28034 Madrid, Spain
9. Department of Cardiology Medizinische Klinik und Poliklinik I, LMU Klinikum der Universität München, Munich, Germany
10. Department of Cardiology, Institution of Medical Science, Uppsala University, 75185 Uppsala, Sweden