Dr Katritsis directs the Department of Cardiology at Athens Euroclinic, Greece, and is a Lecturer on Medicine at Harvard Medical School. He is honorary consultant cardiologist at St Thomas' Hospital, London, a visiting Professor at the City University, London, and part of the Division of Cardiology at Beth Israel Deaconess Medical Center in Boston. He is an active interventional cardiologist and electrophysiologist, and runs multidisciplinary research programmes on a wide range of cardiac disorders. He has published over 300 original articles, and contributed to most European and American textbooks of cardiology. John Camm is Professor of Clinical Cardiology at St George's Hospital Medical School, University of London, and Professor of Cardiology at Imperial College, London. His interests include cardiac arrhythmias, atrial fibrillation, stroke prevention, anticoagulation, clinical cardiac electrophysiology, cardiac pacemakers, and risk stratification in post-myocardial infarction, heart failure and cardiomyopathy patients. Professor Camm is President of the charity Arrhythmia Alliance and co-founded another highly successful medical charity, the Atrial Fibrillation Association. He is Editor-in-Chief of Europace and Clinical Cardiology, editorial board member of a further 15 journals, and Editor of The ESC Textbook of Cardiovascular Medicine. Dr. Gersh's wide interests include the natural history and therapy of acute and chronic coronary artery disease, clinical electrophysiology and in particular atrial fibrillation and sudden cardiac death, the cardiomyopathies and the clinical implications of molecular genetics in hypertrophic cardiomyopathy, cardiac stem cell therapy and the epidemiology of cardiovascular disease in the developing world. Dr. Gersh is the editor of 13 books and is on the editorial board of 25 journals including Circulation, Journal of the American College of Cardiology (Senior Consulting Editor), Nature Cardiovascular Medicine,and The European Heart Journal (2009 Deputy Editor). He is a member of the Advisory Board of the Reynolds Foundation, a Past Chairman of the Council of Clinical Cardiology of the American Heart Association, an at large member of the World Heart Federation's Scientific and Policy Initiatives Committee (SPIC).