1 Department of Paediatric Cardiology, Amalia Children's Hospital, University Medical Centre Nijmegen, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, the Netherlands; Department of Paediatric Cardiology, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Lundlaan 6, 3584 EA Utrecht, the Netherlands. Electronic address: l.m.geerdink@umcutrecht.nl.
2 Department of Medical Psychology, Amalia Children's Hospital, University Medical Centre Nijmegen, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, the Netherlands.
3 Department of Paediatric Cardiology, Amalia Children's Hospital, University Medical Centre Nijmegen, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, the Netherlands; Paediatric Cardiology Unit, Department of Paediatrics, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Centre, Tel Aviv University, 6 Weizmann Street, 6423906, Israel.