title: [Clinical significance of changes in T wave and ST segment amplitudes on electrocardiogram from supine to standing position among children with unexplained chest tightness or pain in resting stage].
abstract: OBJECTIVE
  To investigate the clinical significance of changes in T wave and ST segment amplitudes on electrocardiogram (ECG) from supine to standing position in children with unexplained chest tightness or pain in resting stage.
  
  
  METHODS
  A total of 122 6-14-year-old children with a chief complaint of unexplained chest tightness or pain (resting stage) underwent head-up tilt test (HUTT). According to HUTT results, these children were divided into HUTT-positive (n=61) and HUTT-negative groups (n=61). They underwent 12-lead ECG in the supine and standing positions, and heart rate and T wave and ST segment amplitudes in II, III, aVF and V5 leads were measured.
  
  
  RESULTS
  In the HUTT-negative group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF, and V5 leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitudes in II, aVF and V5 leads were significantly higher in the standing position than in the supine position (P<0.05). In the HUTT-positive group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF and V5 leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitude in V5 lead was significantly higher in the standing position than in the supine position (P<0.05). There were no significant differences between the two groups with respect to ST segment amplitude and T wave amplitude in II, III and aVF leads of the supine or standing position (P>0.05). Compared with the HUTT-negative group, the HUTT-positive group had significantly greater T wave amplitude differences in II, III, aVF and V5 leads, and heart rate difference from supine to standing position (P<0.05).
  
  
  CONCLUSIONS
  Among the children with unexplained chest tightness or pain in resting stage, T wave amplitude differences in II, III, aVF and V5 leads and heart rate difference from supine to standing position are greater in the HUTT-positive group than in the HUTT-negative group. This suggests that the changes in T wave amplitude on ECG from supine to standing position can indicate autonomic nervous system dysfunction.
authors.affiliation: 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. ch.wang@163.com.
authors.forename: Yun-Li
authors.initials: YL
authors.lastname: Li
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Lin
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Kang
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Chu
authors.forename: Jing
authors.initials: J
authors.lastname: Ran
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D001341:Autonomic Nervous System / Q000503:physiopathology; D002637:Chest Pain / Q000503:physiopathology*; D002648:Child; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture; D016683:Supine Position; D018667:Tilt-Table Test