1. Department of Anaesthetics and Critical Care, Harefield Hospital, Royal Brompton and Harefield Clinical Group, Guy’s and St Thomas NHS Foundation Trust, Hill End Road, Uxbridge, London UB9 6JH, UK
2. Department of Cardiology and Rhythmology, Agaplesion Diakone Kliniken Kassel, Herkulesstrasse 34, Kassel DE-34119, Germany
3. Institute of Clinical Physiology, National Research Council, Via G. Moruzzi 1, Pisa 56124, Italy
4. ICCU, Cardiology Department, Sandro Pertini Hospital, Via dei Monti Tiburtini, 385, Roma 00157, Italy
5. Department of Cardiology, Faculty of Medicine, Clinical Hospital Center Zemun, Beograd University School of Medicine, Belgrade, Serbia