2 Cardiovascular Department, "Azienda Sanitaria Universitaria Giu- liano-Isontina", Trieste, Italy; Department of Cardiovascular Science, Faculty of Life Science and Medicine, King's College London, London, UK.
3 Biostatistics Unit, Department of Medical Sciences, University of Trieste, Trieste, Italy.
4 Cardiothoracic Centre, Guy's and St Thomas' Hospital, King's College London, London, UK.
5 Division of Cardiac Electrophysiology, Department of Cardiology, Klinikum Fuerth, Fuerth, Germany.