1. University College London Medical School , 74 Huntley St, London WC1E 6DE , UK
2. Department of Cardiology, Royal Free Hospital , London , UK
3. National Medical Research Association , London , UK
4. Stoke Mandeville Hospital , Aylesbury , UK
5. Brighton And Sussex Medical School, Brighton , UK
6. Oxford Heart Centre, John Radcliffe Hospital , Oxford , UK