[1] Southampton Gen Hosp, Paediat Cardiol, Southampton, Hants, England
[2] Leeds Gen Infirm, Dept Congenital Cardiol, Leeds, W Yorkshire, England
[3] Sheffield Med Sch, Sheffield, S Yorkshire, England
[4] Great Ormond St Hosp Sick Children, Paediat Cardiol, London, England
[5] Bristol Royal Hosp Children, Paediat Cardiol, Bristol, Avon, England