1. Centre for Health Services and Nursing Research, Katholieke Universiteit Leuven, Kapucijnenvoer 35/4, B-3000 Leuven, Belgium
2. Division of Congenital Cardiology, University Hospitals of Leuven, Herestraat 49, B-3000 Leuven, Belgium
3. Department of Pediatric Cardiology, Cliniques Universitaires Saint Luc, Avenue Hippocrate 10, B-1200 Brussels, Belgium
4. Center for Congenital Heart Diseases A. Blancquaert, Ghent University Hospital-University Hospital of Antwerp, De Pintelaan 185, B-9000 Ghent, Belgium
5. Pediatric Cardiology, University Hospitals of Leuven, Herestraat 49, B-3000 Leuven, Belgium
6. Division Pediatric Cardiology, University of Liège at CHR Citadelle, Boulevard du 12ieme de Ligne 1, B-4000 Liège, Belgium
7. Belgian National Foundation for Research in Paediatric Cardiology, Chemin Droleau 2, B-1430 Rebecq, Belgium