1 Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Norway; Institute of Clinical Medicine, University of Oslo, Norway; Department of Pediatric Research, Oslo University Hospital, Norway. Electronic address: [email protected].
2 Department of Pediatric Cardiology, Oslo University Hospital, Oslo, Norway.
3 Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Norway; Institute of Clinical Medicine, University of Oslo, Norway.
4 Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Norway; Department of Pediatric Research, Oslo University Hospital, Norway.