1 Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Austria. Electronic address: Martin.Koestenberger@medunigraz.at.
2 Department of Pediatric Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
3 Departments of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany.