1. Cardiac Pacing and Electrophysiology, Cleveland Clinic , 9500 Euclid Avenue, Cleveland, OH 44118 , USA
2. Karolinska University Hospital Stockholm , 17176 Stockholm , Sweden
3. University Hospital of Geneva , 1205 Geneva , Switzerland
4. Charite Hospital , 10117 Berlin , Germany
5. Maastricht University Medical Center , 6211 LK Maastricht , The Netherlands
6. Department of Cardiology, Faculty of Medicine, Shaare Zedek Medical Center, Hebrew University , Jerusalem 9112001 , Israel
7. Cardio Arrhythmology Center , 00186 Roma , Italy
8. Aarhus University Hospital, Aarhus University , 8200 Aarhus , Denmark