1. Cardiology Unit, “Card. G. Panico” Hospital, 73039 Tricase, Italy
2. Institute of Cardiology, University of Bologna, S. Orsola-Malpighi University Hospital, 40126 Bologna, Italy
3. Division of Cardiology, University of Eastern Piedmont, Maggiore della Carità Hospital, 28100 Novara, Italy
4. Department of Cardiology, Arrhythmology Center, ASL 4 Chiavarese, 16033 Lavagna, Italy
5. Cardiology Unit, Department of Clinical and Experimental Medicine, University of Messina, 98122 Messina, Italy