1. Faculty of Medicine, Department of Cardiology, Clinical Hospital Center Zemun, University of Belgrade, Vukova 9, 11080 Belgrade, Serbia
2. Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
3. Istituto Auxologico Italiano, IRCCS, S. Luca Hospital, Piazzale Brescia 20, Milan, Italy
4. Department of Cardiology, Imperial College Healthcare NHS Trust, London W12 0HS, UK
5. Paediatric Cardiology and Congenital Heart Disease, University of Padua, Italy
6. Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
7. Department of Cardiology & Rhythmology, Agaplesion Diakonie Kliniken, Academic Teaching Hospital University of Marburg, Kassel, Germany
8. Department of Cardiology, Zealand University Hospital, Roskilde, Denmark
9. Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
10. Institute of Clinical Physiology, National Research Council, Pisa, Italy
11. Department of Cardiology, Centrum voor Hart en Vaatziekten, Universitair Ziekenhuis Brussel, Belgium
12. Institute for Clinical Medicine, University of Oslo, Oslo, Norway