title: [Electrocardiographic T-wave amplitude of normal population and its correlation with age, sex and race].
abstract: OBJECTIVE
  To establish a normal electrocardiographic T wave amplitude standard in Chinese population according to age and sex.
  
  
  METHODS
  The electrocardiographic T wave amplitudes in 4,322 persons among normal population; aged from birth to eighty-five years old divided into 11 age-groups, were analyzed. The 97.5th percentile(P97.5) and 2.5th percentile(P2.5) were considered as the upper and the lower limit of normal T wave amplitudes and T/R ratio. Wilcoxon rank sum test was used to determine whether the normal electrocardiographic T wave amplitude and the T/R ratio were different in P97.5 value versus mean + 1.96 s value, in men versus women, and in Chinese versus Americans. The linear correlation analysis was used to examine the association between normal T amplitude and age as well as between T/R ratio and age.
  
  
  RESULTS
  The normal T wave amplitudes and T/R ratio in all leads were greater in P97.5 value than in mean + 1.96 s value and were greater in men than in women. The normal T wave amplitudes of adults were greater in Chinese than in Americans except V1 lead in which the amplitudes were greater in Americans than in Chinese. There was moderate or marked correlation of normal T wave amplitude and T/R ratio with age in most of the leads.
  
  
  CONCLUSIONS
  There are marked differences of age, sex and race in normal electrocardiographic T wave amplitudes.
authors.affiliation: Laboratory of Pediatric Cardiovascular Diseases, Second Affiliated Hospital, Hunan Medical University, Changsha 410011.
authors.forename: Z
authors.initials: Z
authors.lastname: Xie
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D044465:White People