1. Department of Arrhythmology and Electrophysiology, IRCCS Policlinico San Donato , Milano , Italy
2. University San Raffaele Vita & Salute , Milano , Italy
3. IRCCS Istituto Auxologico, University of Milan , Milan , Italy
4. Department of Cardiology, University Medical Center Utrecht , Heidelberglaan 100 , Utrecht, The Netherlands