[1] Univ Gothenburg, Inst Hlth & Care Sci, Box 457, S-40530 Gothenburg, Sweden
[2] Queen Silvias Childrens Hosp, Dept Paediat Cardiol, Rondvagen 10, S-41650 Gothenburg, Sweden
[3] Katholieke Univ Leuven, Dept Publ Hlth & Primary Care, Kapucijnenvoer 35,PB 7001, B-3000 Leuven, Belgium
[4] Univ Cape Town, Dept Paediat & Child Hlth, Klipfrontein Rd Mowbray, ZA-7700 Cape Town, South Africa
[5] Umea Univ, Dept Publ Hlth & Clin Med, S-90185 Umea, Sweden
[6] Uppsala Univ, Dept Med Sci, Cardiol, Sjukhusvagen 7, S-75309 Uppsala, Sweden
[7] Karolinska Univ Hosp, Congenital Heart Dis Grp, Heart & Vasc Theme, S-17176 Solna, Sweden
[8] Karolinska Univ Hosp, Dept Paediat Cardiol, S-17176 Stockholm, Sweden
[9] Skane Univ Hosp, Dept Paediat Cardiol, Barnhjartctr Avd 67, S-22185 Lund, Sweden
[10] Linkoping Univ, Dept Med & Hlth Sci, Div Cardiovasc Med, S-58185 Linkoping, Sweden
[11] Linkoping Univ, Dept Cardiol, Dept Med & Hlth Sci, S-58185 Linkoping, Sweden
[12] Orebro Univ Hosp, Dept Paediat & Womens Hlth Care, S-70185 Orebro, Sweden
[13] Linkoping Univ, Crown Princess Victoria Childrens Hosp, Dept Clin & Expt Med, Div Paediat, S-58185 Linkoping, Sweden
[14] Lund Univ, Skane Univ Hosp, Dept Clin Sci Lund, Dept Paediat Cardiol, S-22185 Lund, Sweden
[15] Uppsala Univ, Dept Paediat Cardiol, Sjukhusvagen 85, S-75185 Uppsala, Sweden
[16] Umea Univ, Umea Univ Hosp, Dept Clin Sci, Unit Paediat, S-90185 Umea, Sweden
[17] Univ Cape Town, Red Cross War Mem Childrens Hosp, Fac Hlth Sci, Dept Paediat & Child Hlth,Div Paediat Cardiol, Klipfrontein Rd Mowbray, ZA-7700 Cape Town, South Africa
[18] Univ Cape Town, Groote Schuur Hosp, Fac Hlth Sci, Dept Med,Div Cardiol, Anzio Rd Mowbray, ZA-7700 Cape Town, South Africa
[19] Res Fdn Flanders FWO, Egrnontstr 5, B-1030 Brussels, Belgium