1. Department of Cardiology, Norfolk and Norwich University Hospital, Colney Lane, Norwich NR4 7UY, UK
2. Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7UG, UK
3. Department of Cardiology, West Suffolk Hospital, Hardwick Ln, Bury Saint Edmunds IP33 2QZ, UK
4. Royal Brompton Hospital, Royal Brompton and Harefield Hospitals, Guy’s and St Thomas’ NHS Foundation Trust, Sydney Street, London SW3 6NP, UK
5. Faculty of Medicine, Imperial College London, London SW7 5NH, UK