1. Electrophysiology Unit, De Gasperis Cardio Center, Niguarda Hospital, 20162 Milan, Italy
2. Clinical Cardiology Unit, De Gasperis Cardio Center, Niguarda Hospital, 20162 Milan, Italy
3. Department of Cardiology, Ospedale Magalini di Villafranca, 37069 Villafranca di Verona, Italy
4. School of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy