1. Vasomotor hot flashes and cardiac repolarization: a randomized placebo-controlled trial of postmenopausal hormone therapy.
- Author
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Lantto H, Haapalahti P, Viitasalo M, Väänänen H, Sovijärvi ARA, Ylikorkala O, and Mikkola TS
- Subjects
- Arrhythmias, Cardiac prevention & control, Double-Blind Method, Estradiol administration & dosage, Female, Heart physiopathology, Heart Diseases physiopathology, Heart Rate, Humans, Medroxyprogesterone Acetate administration & dosage, Middle Aged, Placebos, Electrocardiography, Estrogen Replacement Therapy methods, Heart Diseases prevention & control, Hot Flashes drug therapy, Postmenopause physiology
- Abstract
Objective: The aim of the study was to compare the effects of different hormone therapies on cardiac repolarization in recently postmenopausal women with and without hot flashes., Methods: We recruited 150 healthy women: 72 with and 78 without hot flashes. They were randomized and treated for 6 months with transdermal estradiol (1 mg/day), oral estradiol (OE) alone (2 mg/day) or combined with medroxyprogesterone acetate (MPA; 5 mg/day), or placebo. Cardiac repolarization was assessed by measuring QT intervals, rate-dependence of QT-end interval, and T waves from 24-hour electrocardiographic recording before and during hormone therapy, comprising a total of over 20 million QT-interval measurements., Results: Hot flashes were accompanied with shortened median T-peak - T-end interval (at RR interval of 700, 800, and 900 ms; P = 0.040, 0.020, and 0.032; η = 0.35, 0.39, and 0.37; respectively) during the use of OE but not transdermal estradiol. In contrast, the addition of MPA to OE lengthened the maximal QT-end (at RR interval of 500 ms, P = 0.016, η = 0.27) and the maximal T-peak - T-end interval (at RR interval of 500 and 600 ms; P = 0.016 and 0.032; η = 0.25 and 0.22, respectively). These effects were not seen in women without hot flashes., Conclusions: Hot flashes predict beneficial shortening in cardiac repolarization during OE, but not if MPA is combined with OE. These data may provide one explanation for MPA-related cardiac hazards in epidemiological studies.
- Published
- 2017
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