[1] Univ Padua, Sch Med, Dept Cardiac Thorac & Vasc Sci, Via N Giustiniani 2, I-35121 Padua, Italy
[2] Marien Hosp, Heart Ctr Osnabruck Bad Rothenfelde, Osnabruck, Germany
[3] Tufts Univ, Sch Med, New England Cardiac Arrhythmia Ctr, Boston, MA 02111 USA
[4] ICIN Netherlands Heart Inst, Utrecht, Netherlands
[5] Univ Penn Hlth Syst, Philadelphia, PA USA
[6] Univ Athens, Sch Med, Cardiol Dept 1, GR-11527 Athens, Greece
[7] Univ Zurich Hosp, Ctr Cardiovasc, CH-8091 Zurich, Switzerland
[8] Yannis Protonotarios Med Ctr, Hora Naxos, Greece
[9] Johns Hopkins Univ Hosp, Baltimore, MD 21287 USA
[10] Univ Hosp Munster, Munster, Germany
[11] Ctr Sports Sci, Rome, Italy
[12] Heart Hosp, London, England
[13] Univ Arizona, Tucson, AZ USA