1. Department of Cardiology, St. Mary's Hospital, Imperial College Healthcare NHS Trust, W2 1NY London, UK
2. Department of Cardiology, Ospedale Careggi, 50141 Firenze, Italy
3. Department of Cardiology, Ospedale di Bolzano, 39100 Bolzano, Italy
4. Department of Cardiology, Ospedale di Manduria, 70024 Taranto, Italy
5. Department of Cardiology, Ospedale SS. Antonio e Biagio e Cesare Arrigo, 15121 Alessandria, Italy
6. Department of Cardiology, Presidio Ospedaliero di Casarano, 73042 Lecce, Italy
7. Department of Cardiology, Hospital Xeral de Vigo, 36201 Vigo, Spain
8. Department of Cardiology, Arcispedale S. Maria Nuova, 42121 Reggio Emilia, Italy
9. Department of Cardiology, Kardiologische Gemeinschaftspraxis, 01587 Riesa, Germany
10. Department of Cardiology, Ospedale Garibaldi-Nesima, 95100 Catania, Italy
11. Department of Cardiology, Ospedale S. Giovanni Battista Le Molinette, 10100 Torino, Italy
12. Department of Cardiology, Medtronic Italia, 95100 Rome, Italy
13. Department of Cardiology, Hospital Universitario Vall d'Hebron, 95100 Barcelona, Spain
14. Department of Cardiology, Vivantes Klinikum Am Urban, Berlin 10100, Germany
15. Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, 16033 Lavagna, Italy