[1] Leeds Gen Infirm, Dept Congenital Cardiol, Leeds LS1 3EX, W Yorkshire, England
[2] Sussex Cardiac Ctr, Dept Cardiol, Brighton, E Sussex, England
[3] Queen Elizabeth Hosp, Dept Adult Congenital Heart Dis, Birmingham B15 2TH, W Midlands, England
[4] Bristol Heart Inst, Dept Congenital Cardiol, Bristol, Avon, England
[5] John Radcliffe Hosp, Dept Cardiovasc Med, Oxford OX3 9DU, England
[6] Univ Oxford, Radcliffe Dept Med, Div Cardiovasc Med, Oxford, England
[7] Univ Nottingham Hosp, Trent Cardiac Ctr, Dept Cardiol, Nottingham NG7 2UH, England
[8] Royal Victoria Hosp, Dept Cardiol, Belfast BT12 6BA, Antrim, North Ireland
[9] Manchester Royal Infirm, Dept Cardiol, Manchester M13 9WL, Lancs, England
[10] Freeman Rd Hosp, Dept Paediat Cardiol, Newcastle Upon Tyne NE7 7DN, Tyne & Wear, England