title: QT interval and final portion of T wave: measurements and dispersion in infants born at high altitude.
abstract: BACKGROUND
  This research was conducted to determine whether the depolarization and repolarization cardiac process of children born at high altitude differs from that of children born at lower altitudes.
  
  
  METHODS
  We studied three groups of 30 healthy newborns in the Venezuelan Andes. Group 3500 m consisted of infants born at 3500 m above sea level; Group 3000 m of infants born at 3000 m above sea level and Group 1600 m of infants born at 1600 m above sea level. Conventional 12-lead electrocardiograms were recorded in the 90 newborns. Corrected QT interval, duration from the peak to the end of the T wave, dispersion of QT interval and of the final portion of T wave and heart rate were computed in each subject.
  
  
  RESULTS
  The findings of the present study show that infants born at high altitude (Groups 3500 and 3000 m) had a significantly longer corrected QT interval and a significantly shorter peak-to-end of T wave interval. Neither the heart rate nor the indexes of dispersion of the depolarization-repolarization process revealed abnormal values or significant differences among the groups.
  
  
  CONCLUSIONS
  These results suggest that the depolarization and repolarization cardiac process of infants born at high altitude differs from that of children born at lower altitudes.
authors.affiliation: Clinical Electrophysiology Section, Dr. Abdel M. Fuenmayor P. Cardiovascular Research Institute, University of The Andes, Apartado Postal 154, Mérida, 5101 Venezuela. ajf@cantv.net
authors.forename: Abdel J
authors.initials: AJ
authors.lastname: Fuenmayor
authors.forename: Frances U
authors.initials: FU
authors.lastname: Stock
authors.forename: Akbar C
authors.initials: AC
authors.lastname: Fuenmayor
authors.forename: Abdel M
authors.initials: AM
authors.lastname: Fuenmayor P
mesh_terms: D000531:Altitude; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008297:Male