1. Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
2. Department of Electrophysiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
3. Statistics Advisory Service, Imperial College London, London, UK
4. Department of Cardiology, Royal Brompton Hospital, London, UK