1 Department of Cardiology and Cardiothoracic Surgery, Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy. Electronic address: mazzone.patrizio@hsr.it.
2 Department of Cardiology and Cardiothoracic Surgery, Arrhythmia Unit and Electrophysiology Laboratories, Ospedale San Raffaele, Milan, Italy.