Region Västra Götaland, Children’s Heart Center, Queen Silvia Children’s Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden (K.L., M.M.); Department of Pediatrics, Institution of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden (K.L., I.Ö.-S., A.E., M.M.); Department of Pediatric Cardiology, Stockholm-Uppsala, Karolinska University Hospital, Stockholm, Sweden (K.K., G.B.); Department of Women’s and Children’s Health, Karolinska Institute, Stockholm, Sweden (K.K., G.B.); Department of Cardiology, Pediatric Heart Center, Skåne University Hospital Lund, Lund University, Lund, Sweden (P.L.); Department of Clinical Sciences, Pediatrics, Umeå Univeristy, Umeå, Sweden (J.A.D.); and Region Västra Götaland, Department of Pediatrics, Queen Silvia Children’s Hospital, Sahlgrenska Univeristy Hospital, Gothenburg, Sweden (A.E.)