1. Ospedale Madre Giuseppina Vannini, Rome
2. Cardiology Division, Department of Diagnostics, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Policlinico di Modena, Modena
3. Department of Cardiology, Ospedale SS.ma Annunziata, Azienda Unità Sanitaria Locale Ferrara, Cento, Italy
4. CHU Pontchaillou, Rennes, France
5. Policlinico Casilino, Rome
6. Heart Rhythm Center, Centro Cardiologico Monzino, Milan, Italy
7. CH Président F. Mitterand, Pau, France
8. Hospital Universitario Puerta de Hierro, Madrid, Spain
9. Institute of Cardiology, University of Bologna, Azienda Ospedaliera S.Orsola-Malpighi, Bologna, Italy
10. St Jude Medical, Zaventem, Belgium
11. St Jude Medical, Milan, Italy