Dr John Walker is a Consultant Cardiologist at The Harley Street Clinic, HCA UK at University College Hospital and for the Barts Health NHS Trust. He specialises in cardiac rehabilitation, cardiovascular disease associated with inherited haemoglobinopathies - Thalassaemia and Sickle Cell disease.

He graduated from the University of Birmingham (honours in pre-clinical sciences) before specialising in cardiology at St.Thomas' Hospital & the Brompton Hospital, London and at the John Radcliffe Hospital, Oxford. His MD in 1983 involved studying the mechanical performance of human heart muscle. In 1987 he was appointed as Consultant Cardiologist to University College and the Middlesex Hospitals.

As a consequence of his interest in patients with inherited diseases of haemoglobin, he established The Thalassaemia and Sickle Cardiac Centre at the Hatter Cardiovascular Institute, UCLH. This was the world's first cardiology clinic dedicated to diagnosing and treating young patients with inherited haemoglobinopathies.

Dr Walker is highly active in clinical research, with more than 60 publications in scientific and medical journals. He has made numberous book contribitions, including authorship of the cardiovascular disease chapeters of a major English language textbook of medicine. He was the Treasurer and then President of the British Association of Cardiovascular Rehabilitation from 2001 to 2006, as well as a Council member of the British Cardiovascular Society.

• Cardia Magnetic Resonance Scan (cardaic MRI)
• ECG (electrocardiogram)

• Paediatric congenital heart disease (CHD)