1. Department of Pediatrics, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
2. Division of Pediatric Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3. Division of Cardiology, Department of Pediatrics, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
4. Department of Pediatrics, Kyung Hee University Hospital, Seoul, Korea.
5. Green Cross Corporation, Seoul, Korea.
6. Division of Cardiology, Department of Pediatrics, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.