1. Division of Neonatology and
2. Department of Paediatrics and
3. Department of Paediatrics, The Rotunda Hospital, Dublin, Ireland; and
4. Department of Paediatrics, School of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
5. Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, Canada
6. Department of Physiology, The University of Toronto, Toronto, Ontario, Canada