1. Department of Cardiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
2. Department of Cardiology, National Heart Center Singapore, Singapore Duke-NUS Graduate Medical School, 5 Hospital Dr, 169609 Singapore, Singapore
3. Department of Pediatric Cardiology, Center for Congenital Heart Diseases, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB Groningen, The Netherlands