1. Electrophysiology Laboratory and First University Department of Cardiology; Hippokration General Hospital; National and Kapodestrian University of Athens; Athens Greece
2. Department of Cardiology; Hippokration General Hospital; Athens Greece
3. Electrophysiology Laboratory Athens Medical Center; Athens Greece
4. Department of Cardiology; University of Ioannina; Ioannina Greece
5. Cardiovascular Research Institute; Ioannina Greece