1. Cardiology Unit, Department of Emergency, Umberto Primo Hospital, 94100 Enna, Italy
2. Section of Cardiology, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98122 Messina, Italy
3. Cardiothoracic Department, Policlinico Riuniti University Hospital, 71122 Foggia, Italy
4. Cardiology Unit, Department of Emergency, Umberto Primo Hospital, 96100 Siracusa, Italy