1. Institution of Clinical Science, Paediatrics Umeå University Umeå Sweden
2. Department of Cardiology, Paediatric Heart Centre, Queen Silvia's Children's Hospital, Institution of Clinical Sciences, Department of Paediatrics University of Gothenburg Gothenburg Sweden
3. Department of Cardiology, Paediatric Heart Centre Skåne University Hospital Lund and Lund University Lund Sweden
4. Department of Women's and Children's Health Karolinska Institute Stockholm Sweden