1. From National Heart and Lung Institute (G.-P.D., K.D., M.A.G., D.P.F.), Imperial College of Science and Medicine, London, United Kingdom; Adult Congenital Heart Disease Unit (G.-P.D., A.U., K.D., M.A.G.), Royal Brompton Hospital, London, United Kingdom; Department of Paediatric Cardiology and Biomedical Engineering (A.U.), University Hospital of Schleswig-Holstein, Kiel, Germany; International Centre for Circulatory Health (K.W., D.P.F.), Imperial College of Science and Medicine, London, United...