title: Gender differences in the dynamics of terminal T wave intervals.
abstract: This study was designed to investigate gender differences in the dynamic changes of the terminal T wave (Ta-e interval) of healthy subjects. Holter ECGs were recorded in 24 healthy volunteers (12 men aged 23 +/- 2 years). The intervals from QRS onset to the apex (QaT) and to the end of the T wave (QeT), and the interval between the apex and the end of the T wave (Ta-e) were measured. Then, the QeT/RR, QaT/RR, and Ta-e/RR relationship was evaluated by linear regression analysis in each subject. The QeT and QaT intervals were significantly longer in women than men and the slope of the QeT/RR and QaT/RR relationship was steeper in women than men. The Ta-e intervals showed a significant but weaker positive correlation with the preceding RR intervals in 7 (58.3%) men and 9 (75.0%) women. The average values of the slope and the correlation coefficient of the Ta-e/RR relationship were significantly smaller compared to those of QeT and QaT in both men and women (P < 0.0001). The slope of the Ta-e/RR relationship was significantly greater in women than men (0.025 +/- 0.009 vs 0.011 +/- 0.012, P < 0.005). However, the Ta-e intervals were significantly longer over the entire range of RR intervals in men than women (P < 0.0001). The rate-correcting formulas of Bazett and Framingham overcorrected the Ta-e intervals. The observed gender difference in the measurement and dynamics of the Ta-e interval may help to understand the mechanisms underlying the gender difference in the incidence of ventricular arrhythmias.
authors.affiliation: Department of Cardiovascular Science, Division of Laboratory Medicine, Oita University School of Medicine, Oita, Japan. mikinak@med.oita-u.ac.jp
authors.forename: Mikiko
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Ooie
authors.forename: Baiqing
authors.initials: B
authors.lastname: Ou
authors.forename: Masashi
authors.initials: M
authors.lastname: Ichinose
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yonemochi
authors.forename: Tetsunori
authors.initials: T
authors.lastname: Saikawa
mesh_terms: D000328:Adult; D016477:Artifacts; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation*; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008297:Male; D012016:Reference Values; D012727:Sex Characteristics; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012984:Software