[1] Hope Childrens Hosp, Heart Inst Children, Sect Perinatal Cardiol, Oak Lawn, IL USA
[2] Alberta Childrens Prov Gen Hosp, Cardiol Sect, Dept Pediat, Calgary, AB T2T 5C7, Canada
[3] Univ Cincinnati Hosp, Inst Heart, Dept Pediat, Cincinnati, OH USA
[4] Hosp Sick Children, Sect Pathol, Dept Pediat Lab Med, Toronto, ON M5G 1X8, Canada
[5] Hosp Sick Children, Dept Pediat, Cardiol Sect, Toronto, ON M5G 1X8, Canada
[6] Vanderbilt Univ, Div Cardiol, Dept Pediat, Monroe Carell Jr Childrens Hosp, Nashville, TN 37232 USA
[7] Karolinska Inst, Dept Med, Rheumatol Unit, Stockholm, Sweden
[8] Royal Brompton Hosp, Cardiac Morphol Unit, London SW3 6LY, England