1. Department of Paediatric Cardiology Queen Silvia Children′s Hospital Sahlgrenska University Hospital Gothenburg Sweden
2. Department of Paediatric Cardiology Skåne University Hospital Lund Sweden
3. Department of Pediatric Cardiology Karolinska University Hospital Stockholm Sweden
4. Department of Paediatric Cardiac Surgery Skåne University Hospital Lund Sweden
5. Statistiska konsultgruppen Gothenburg Sweden
6. Department of Clinical Sciences, Paediatrics Umeå University Umeå Sweden
7. Department of Women's and Children's Health Karolinska Institutet Stockholm Sweden