1. Department of Medical Sciences, Cardiology and Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden
2. Division of Cardiology, C.A.S.T., P.O. “G. Rodolico”, Azienda Ospedaliero-Universitaria “Policlinico-Vittorio Emanuele”, University of Catania, Catania, Italy
3. Division of Cardiology, University of Florida College of Medicine, Jacksonville, FL, USA