1. Department of Cardiology, University Hospital Coventry and Warwickshire NHS Trust , Clifford Bridge Road, Walsgrave, Coventry, CV2 2DX , UK
2. Electrophysiology Division, Abbott Laboratories , Solihull , UK
3. Arrhythmia Unit, Hospital Clínic de Barcelona , Barcelona , Spain
4. Institute of Cardiovascular Science, University College London , London , UK
5. University of Warwick, Warwick Medical School , Coventry, CV4 7HL , UK