1. Division of Cardiology, A.O.U. Policlinico “G. Rodolico San Marco”, 95123 Catania, Italy
2. Faculty of Medicine and Surgery, Università degli Studi di Enna “Kore”, 94100 Enna, Italy
3. Division of Cardiology, Ospedale Umberto I, ASP 4 di Enna, 94100 Enna, Italy