1. Department of Congenital Cardiology; Evelina Children's Hospital; London; United Kingdom
2. Department of Paediatric Cardiology; The Children's Hospital/The Institute of Child Health and Punjab Institute of Cardiology; Lahore; Pakistan
3. Heart Catheterization Laboratory; The Children's Memorial Health Institute; Warsaw; Poland
4. Department of Congenital Cardiology; Leeds General Infirmary; Leeds; United Kingdom