By Daniel Aston (BSc, MBBS, MRCP, FRCA), Angus Rivers (BSc, Asela Dharmadasa (MA, BM BCh
By John Hampton (Emeritus Professor of Cardiology, University of Nottingham, Nottingham, UK), Joanna Hampton, MD, MA, BM BCh, FRCP (Consultant Physician, Addenbrooke's Hospital, Cambridge)