title: Electrocardiographic P-Wave Duration, QT Interval, T Peak to End Interval and Tp-e/QT Ratio in Pregnancy with Respect to Trimesters.
abstract: BACKGROUND
  P-wave duration helps to determine the risk of atrial arrhythmia, especially atrial fibrillation. QT interval, T peak to end interval (Tp-e), and Tp-e/QT ratio are electrocardiographic indices related to ventricular repolarization which are used to determine the risk of ventricular arrhythmias. We search for any alterations in electrocardiographic indices of arrhythmia in the pregnancy period with respect to trimesters.
  
  
  METHODS
  We enrolled 154 pregnant and 62 nonpregnant, healthy women into this cross-sectional study. Maximum and minimum P-wave durations (Pmax, Pmin), and QT intervals (QTmax, QTmin) were measured from 12 leads. QT measurements were corrected using Fridericia (QTc-Fr) and Bazett's (QTc-Bz) correction. Tp-e interval was obtained from the difference between QT interval, and QT peak interval (QTp) measured from the beginning of the QRS until the peak of the T wave. Tp-e/QT ratio was calculated using these measurements.
  
  
  RESULTS
  Pmax were 93.0 ± 9.1, 93.9 ± 8.9, 97.9 ± 5.6, 99.0 ± 6.1 in nonpregnant women, first, second, third trimesters of pregnancy, respectively (P = 0.001); whereas Pmin values were not significantly different. QTc-Fr max were 407.4 ± 14.2, 408.5 ± 16.1, 410.1 ± 13.1, 415.1 ± 10.1 (P = 0.007); Tp-e were 72.7 ± 6.2, 73.2 ± 6.5, 77.2 ± 8.9, 87.2 ± 9.6 (P < 0.001); and Tp-e/QT were 0.17 (0.14-0.20), 0.17 (0.14-0.20), 0.18 (0.15-0.23), 0.20 (0.16-0.25) in nonpregnant women, first, second, and third trimesters of pregnancy respectively (P < 0.001). None of the participants experienced any arrhythmic event.
  
  
  CONCLUSIONS
  P-wave duration is prolonged in the second trimester, and resumes a plateau thereafter. Maximum QTc interval, Tp-e interval and Tp-e/QT ratio are increased in the late pregnancy. Although these indices are altered during the course of pregnancy, they all remain in the normal ranges.
authors.affiliation: Department of Cardiology, Ufuk University Faculty of Medicine, Ankara, Turkey.
authors.forename: Asli
authors.initials: A
authors.lastname: Tanindi
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Özal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Nilufer
authors.initials: N
authors.lastname: Akgun
authors.affiliation: Department of Obstetrics and Gynecology, Ufuk University Faculty of Medicine, Ankara, Turkey.
authors.forename: Emre Goksan
authors.initials: EG
authors.lastname: Pabuccu
authors.affiliation: Department of Obstetrics and Gynecology, Ufuk University Faculty of Medicine, Ankara, Turkey.
authors.forename: Aslı Yarci
authors.initials: AY
authors.lastname: Gursoy
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Özal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Yüce
authors.affiliation: Department of Cardiology, Ufuk University Faculty of Medicine, Ankara, Turkey.
authors.forename: Hasan Fehmi
authors.initials: HF
authors.lastname: Tore
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Özal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Candan Iltemir
authors.initials: CI
authors.lastname: Duvan
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D011247:Pregnancy; D011264:Pregnancy Trimesters; D013995:Time; D055815:Young Adult
keywords: P-wave duration; QT interval; T peak to end interval; Tp-e/QT ratio