1. Clinic of Pediatric Cardiology and Cardiac Surgery; University Hospital for Children; Riga; Latvia
2. Departament of Pediatrics; Riga Stradin's University; Riga; Latvia
3. Cell Transplantation Centre; Pauls Stradins Clinical University Hospital; Riga; Latvia
4. The Latvian Institute of Cardiology; Pauls Stradins Clinical University Hospital; Riga; Lativa