Professor John Deanfield is a Professor of Cardiology at University College London. He has particular interest in paediatric cardiology and currently focuses on endothelial function and congenital heart disease.He received his medical degree in 1975 form the University of Cambridge. He then underwent clinical training at Middlesex Hospital, London and postgraduate training in paediatric cardiology at Great Ormond Street Hospital and adult cardiology at Hammersmith Hospital.He was first appointed as a Consultant in 1984 and has over 34 years of consultant experience. He is a Fellow of the Royal College of Physicians, the European Society of Cardiology and the American College of Cardiology.During his career he developed one of the largest programmes in the world that provides services for patients with Adult Congenital Heart Disease.Professor Deanfield is also the Director of the National Institute of Cardiovascular Outcomes Research and a Senior Advisor to Public Health England, using his expertise in cardiology to advise the government on cardiovascular disease prevention.In his current practice, he regularly performs: screening for congenital heart defects in both adults and children, foetal cardiac screening and screening for congenital heart disease. He treats patients with abnormal endothelial function, atherosclerosis and offers his expertise to those with familial risk of heart disease.Professor Deanfield is a member of many professional organisations and is on a number of editorial boards for renowned cardiovascular journals. He has published over 450 papers into peer-reviewed journals and is still actively involved in research. He has been awarded several prizes for his work.