Electrocardiographic P-Wave Duration, QT Interval, T Peak to End Interval and Tp-e/QT Ratio in Pregnancy with Respect to Trimesters

• Published in: Annals of noninvasive electrocardiology 2016-03, Vol.21 (2), p.169-174
• Main Authors: Tanindi, Asli, Akgun, Nilufer, Pabuccu, Emre Goksan, Gursoy, Aslı Yarci, Yüce, Ebru, Tore, Hasan Fehmi, Duvan, Candan Iltemir
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Cross-Sectional Studies; Electrocardiography - methods; Electrocardiography - statistics & numerical data; Female; Heart Conduction System - physiology; Heart Rate - physiology; Humans; Original; P-wave duration; Pregnancy; Pregnancy Trimesters; QT interval; T peak to end interval; Time; Tp-e/QT ratio; Young Adult
• ISSN: 1082-720X; 1542-474X
• DOI: 10.1111/anec.12285

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.