title: Reference values of electrocardiogram repolarization variables in a healthy population.
abstract: BACKGROUND
  Reference values for T-wave morphology analysis and evaluation of the relationship with age, sex, and heart rate are lacking in the literature. In this study, we characterized T-wave morphology in a large sample of healthy individuals.
  
  
  METHODS
  A total of 1081 healthy subjects (83% men; range, 17-81 years) were included. T-wave morphology variables describing the duration, area, slopes, amplitude, and distribution were calculated using 10-second digital electrocardiogram recordings. Multivariate regression was used to test for dependence of T-wave variables with the subject age, sex, and heart rate.
  
  
  RESULTS
  Lead V5 (men vs women) T-wave variables were as follows: amplitude, 444 versus 317 muV; area, 48.4 versus 33.2 ms mV; Tpeak-Tend interval, 94 versus 92 milliseconds; maximal descending slope, -5.15 versus -3.69 muV/ms; skewness, -0.24 versus -0.22; and kurtosis, -0.36 versus -0.35. Tpeak-Tend interval, skewness, and kurtosis were independent of age, sex, and heart rate (r(2) < 0.05), whereas Bazett-corrected QT-interval was more dependent (r(2) = 0.40).
  
  
  CONCLUSIONS
  A selection of T-wave morphology variables is found to be clinically independent of age, sex, and heart rate, including Tpeak-Tend interval, skewness, and kurtosis.
authors.affiliation: The Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Haarmark
authors.forename: Claus
authors.initials: C
authors.lastname: Graff
authors.forename: Mads P
authors.initials: MP
authors.lastname: Andersen
authors.forename: Thomas
authors.initials: T
authors.lastname: Hardahl
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: Struijk
authors.forename: Egon
authors.initials: E
authors.lastname: Toft
authors.forename: Joel
authors.initials: J
authors.lastname: Xue
authors.forename: Gordon I
authors.initials: GI
authors.lastname: Rowlandson
authors.forename: Peter R
authors.initials: PR
authors.lastname: Hansen
authors.forename: Jørgen K
authors.initials: JK
authors.lastname: Kanters
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000592:standards* / Q000706:statistics & numerical data*; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult