1. Department of Electrophysiology, National Heart Hospital, 65 Konyovitza Street, 1309 Sofia, Bulgaria
2. Cardiovascular Institute, Hospital Clínic Pediatric Arrhythmia Unit, Hospital Sant Joan de Déu University of Barcelona, Barcelona, Spain
3. Department of Cardiology, Cardiovascular Institute, Hospital Clinic de Barcelona, Universitat de Barcelona, Spain, Institut d’Investigació August Pi i Sunyer (IDIBAPS), Barcelona, Spain, Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
4. EURObservational Research Programme (EORP), Scientific Division, European Society of Cardiology, Sophia-Antipolis, France
5. ANMCO Research Center, Florence, Italy
6. Department of Medical Science and Cardiology, Uppsala University, Uppsala, Sweden
7. Institute for Clinical and Experimental Medicine (IKEM), Prague, Czech Republic
8. Maria Cecilia Hospital, GVM Care & Research, Cotignola, Ravenna, Italy
9. Humanitas Mater Domini Hospital, Castellanza, Italy
10. Department of Cardiology, Grochowski Hospital Postgraduate Medical School, Warsaw, Poland
11. Pauls Stradins Clinical University Hospital, Latvian Centre, of Cardiology, Riga, Latvia
12. 2nd Department of Medicine and Cardiology Center, University of Szeged, Szeged, Hungary
13. Hospital Universitario Insular de Gran Canaria, Cardiology, Las Palmas de Gran Canaria, Spain
14. Department of Electrophysiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany