CJCP     2015 17 (10):  1070-1073    ISSN: 1008-8830  CN: 43-1301/R Time-dependent heart rate variability in the head-up tilt test in children with postural orthostatic tachycardia syndrome RAN Jing, WANG Cheng, ZOU Run-Mei, WU Li-Jia, LIN Ping, LI Fang, XU Yi Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital of Central South University/Institute of Pediatrics of Central South University, Changsha 410011, China Received: 2015-02-09  Revised: 2015-04-17  Online: null Supporting info null