1. Cardiology Division, Liverpool Heart and Chest Hospital , Liverpool , UK
2. Arrhythmia Section, Cardiology Department, Hospital Universitari Doctor Josep Trueta and Institut d'Investigació Biomèdica de Girona (IDIBGI) , Girona , Spain
3. Cardiac Rhythm Management, Medtronic plc , 8200 Coral Sea Street, MVC71 Mounds View, MN 55112 , USA
4. Medtronic International Trading Sàrl , Tolochenaz , Switzerland
5. Department of Medicine, Division of Cardiology, Emory University Hospital , Atlanta, GA , USA