1 Division of Pediatric Cardiology, University Childrens Hospital Ulm, Ulm, Germany. (Email: christian.apitz@uniklinik-ulm.de).
2 Department of Pediatric Cardiology, Clinic for Adult Congenital and Structural Heart Disease, University Hospital Münster, Münster, Germany. (Email: Astrid.Lammers@ukmuenster.de).