Background: Although gender differences in the corrected QT interval (QT,) have been described, gender differences in QT dispersion (QTd) have not been carefully evaluated. This study was designed to measure QTd in 22 young healthy women and in 20 healthy men.Methods and Results: Twelve-lead ECGs were recorded at rest and following double autonomic blockade with atropine 0.04 mg/kg and propranolol 0.2 mg/kg during the menstrual, follicular, and luteal phases of the menstrual cycle, which was confirmed by hormone levels. Men were studied during three separate visits as controls. In women, there was no difference in QTd among the three phases of the menstrual cycle, and thus all three visits were pooled for comparison with men. The 12-lead QT dispersion (maximumminimum QT) was larger in men than in women at baseline (41 t 17 ms vs 35 5 16 ms), and this difference tended to decrease after double autonomic blockade (35 t 14 ms vs 32 2 11 ms). The standard deviation of the QT interval across the 12 leads was larger in men than in women at baseline (12.6 ? 4.5 vs 10.8 2 4.1), and this difference was no longer significant after double autonomic blockade (10.4 2 4.4 vs 10.1 ? 3.5). QT dispersion was significantly reduced by autonomic blockade (P < 0.05). Conclusions:(1) Double autonomic blockade slightly reduces QTd. (2) QTd is higher in men than in women at baseline but more similar after autonomic blockade. These findings may contribute to the gender difference in the corrected QT interval. (3) Increased female QTd is not the mechanism of increased female susceptibility to torsade de pointes. The clinical implications of gender differences in QTd and QT, remain to be defined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.