Dr. John Walker is a consultant cardiologist specializing in cardiac rehabilitation and cardiovascular disease associated with inherited haemoglobinopathies, such as thalassaemia and sickle cell disease. He graduated with honors in pre-clinical sciences from the University of Birmingham and specialized in cardiology at St. Thomas' and the Brompton, London, and the John Radcliffe, Oxford. Dr. Walker's MD involved studying the mechanical performance of human heart muscle. In 1987, he was appointed as a consultant cardiologist. He established the Thalassaemia and Sickle Cardiac Centre, dedicated to diagnosing and treating young patients with inherited haemoglobinopathies. Dr. Walker is active in clinical research with over 60 publications in scientific and medical journals and numerous book contributions. He has served as Treasurer and President of the British Association of Cardiovascular Rehabilitation and as a Council member of the British Cardiovascular Society. His clinical expertise includes cardiac magnetic resonance imaging (cardiac MRI), ECG (electrocardiogram), and paediatric congenital heart disease (CHD).