[1] Royal Brompton & Harefield NHS Fdn Trust, Royal Brompton Hosp, Adult Congenital Heart Ctr, Sydney St, London SW3 6NP, England
[2] Royal Brompton & Harefield NHS Fdn Trust, Royal Brompton Hosp, Natl Ctr Pulm Hypertens, Sydney St, London SW3 6NP, England
[3] Imperial Coll London, Natl Heart & Lung Inst, Guy Scadding Bldg,Cale St, London SW3 6LY, England
[4] Univ Cincinnati, Cincinnati Childrens Hosp, Dept Pediat, Heart Inst,Coll Med, Cincinnati, OH 45229 USA