1. Division of Cardiology, S. Maria Goretti Hospital, Latina, Italy
2. Texas Cardiac Arrythmia Institute, St David’s Medical Center, Austin, TX 78705, USA
3. Division of Cardiology, S. Carlo Hospital, Potenza, Italy
4. Department of Medico-Surgical Sciences & Biotechnologies, Sapienza University of Rome, Latina, Italy
5. Mediterranea Cardiocentro, Napoli, Italy