1. Department of Medical Sciences, Cardiology and Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden
2. Division of Cardiology, University of Florida College of Medicine, Jacksonville, FL, USA
3. Division of Cardiology, C.A.S.T., P.O. ‘G. Rodolico,’ Azienda Ospedaliero-Universitaria ‘Policlinico-Vittorio Emanuele,’ P.O. Rodolico, Ed. 8, Via Santa Sofia 78, Catania, Sicilia, Italy