[1] Western Univ, Dept Pediat, Pediat Cardiol, London, ON N6A 3K7, Canada
[2] Univ Med Ctr, Dept Pediat Cardiol Intens Care Med & Neonatol, D-37075 Gottingen, Germany
[3] Hannover Med Sch, Dept Pediat Cardiol & Intens Care Med, D-30625 Hannover, Germany
[4] Children Hlth Res Inst, London, ON N6A 5W9, Canada
[5] Hannover Med Sch, Med Sociol Unit, D-30625 Hannover, Germany