[1] Great Ormond St Hosp Sick Children, London WC1N 3JH, England
[2] Hosp Sick Children, Div Cardiol, Toronto, ON M5G 1X8, Canada
[3] Univ Med Ctr Groningen, Dept Pediat Cardiol, NL-9713 AV Groningen, Netherlands
[4] Univ Oklahoma, Oklahoma City, OK USA
[5] Royal Childrens Hosp, Melbourne, Vic, Australia
[6] Toho Univ, Omori Med Ctr, Tokyo, Japan
[7] Childrens Hosp & Reg Med Ctr, Seattle, WA USA
[8] Columbia Univ, New York, NY USA
[9] Univ Geneva, Childrens Hosp, Geneva, Switzerland