[1] IRCCS Policlin San Donato, Arrhythmia & Electrophysiol Ctr, Milan, Italy
[2] Johns Hopkins Univ, Sch Med, Baltimore, MD USA
[3] St Marys Hosp, London, England
[4] Tsuchiura Kyodo Gen Hosp, Ctr Cardiovasc, Tsuchiura Ibaraki, Japan
[5] Royal Melbourne Hosp, Parkville, Vic 3050, Australia
[6] Asan Med Ctr, Dept Cardiol, Seoul, South Korea
[7] Univ Western Ontario Hosp, Dept Cardiol, London, ON N6A 5A5, Canada
[8] St Davids Med Ctr, Texas Arrhythmia Inst, Austin, TX USA
[9] Mayo Fdn St Mary Hosp, Div Cardiol, Rochester, MN USA
[10] Univ Milan, Inst Med Stat & Biometry GA Maccacaro, Milan, Italy