CONTEXT: Women have a higher incidence of torsades de pointes than men, but it is not known if the risk of drug-induced torsades de pointes varies during the menstrual cycle. OBJECTIVES: To determine if the degree of QT prolongation in response to ibutilide varies with the menstrual cycle phase and to compare QT prolongation between women and men. DESIGN AND SETTING: Cohort study of men and women who received the same intervention conducted between November 1998 and November 2000 at a general clinical research center of a university hospital. PARTICIPANTS: A volunteer sample of 58 healthy adults (38 men and 20 women) aged 21 to 40 years. INTERVENTION: A low dose of ibutilide (0.003 mg/kg), infused intravenously for 10 minutes. Subjects were monitored for 120 minutes. Women received the intervention on 3 separate occasions to correspond with menstrual cycle phases, which were verified by using hormonal assays. MAIN OUTCOME MEASURE: QT interval, recorded from electrocardiogram at timed intervals during and after ibutilide infusion and standardized for variations in heart rate (QTc). RESULTS: Maximum (mean [SD]) millisecond increase in QTc after ibutilide infusion was greater for women during menses (63 [13]) and the ovulatory phase (59 [17]) compared with women during the luteal phase (53 [14]) and compared with men (46 [16]; P =.002 vs menses and P =.007 vs ovulation). Progesterone (r = -0.40) and progesterone-to-estradiol ratio (r = -0.41), but not estradiol (r = 0.14) or testosterone (r = 0.09), were inversely correlated with ibutilide-induced QT prolongation. CONCLUSIONS: Menstrual cycle and sex differences exist in QTc responses to ibutilide, with the greatest increase in QTc corresponding to the first half of the menstrual cycle.
CONTEXT: Women have a higher incidence of torsades de pointes than men, but it is not known if the risk of drug-induced torsades de pointes varies during the menstrual cycle. OBJECTIVES: To determine if the degree of QT prolongation in response to ibutilide varies with the menstrual cycle phase and to compare QT prolongation between women and men. DESIGN AND SETTING: Cohort study of men and women who received the same intervention conducted between November 1998 and November 2000 at a general clinical research center of a university hospital. PARTICIPANTS: A volunteer sample of 58 healthy adults (38 men and 20 women) aged 21 to 40 years. INTERVENTION: A low dose of ibutilide (0.003 mg/kg), infused intravenously for 10 minutes. Subjects were monitored for 120 minutes. Women received the intervention on 3 separate occasions to correspond with menstrual cycle phases, which were verified by using hormonal assays. MAIN OUTCOME MEASURE: QT interval, recorded from electrocardiogram at timed intervals during and after ibutilide infusion and standardized for variations in heart rate (QTc). RESULTS: Maximum (mean [SD]) millisecond increase in QTc after ibutilide infusion was greater for women during menses (63 [13]) and the ovulatory phase (59 [17]) compared with women during the luteal phase (53 [14]) and compared with men (46 [16]; P =.002 vs menses and P =.007 vs ovulation). Progesterone (r = -0.40) and progesterone-to-estradiol ratio (r = -0.41), but not estradiol (r = 0.14) or testosterone (r = 0.09), were inversely correlated with ibutilide-induced QT prolongation. CONCLUSIONS: Menstrual cycle and sex differences exist in QTc responses to ibutilide, with the greatest increase in QTc corresponding to the first half of the menstrual cycle.
Authors: Jonathan Buber; Jehu Mathew; Arthur J Moss; W Jackson Hall; Alon Barsheshet; Scott McNitt; Jennifer L Robinson; Wojciech Zareba; Michael J Ackerman; Elizabeth S Kaufman; David Luria; Michael Eldar; Jeffrey A Towbin; Michael Vincent; Ilan Goldenberg Journal: Circulation Date: 2011-05-31 Impact factor: 29.690
Authors: James E Tisdale; Heather A Jaynes; Brian R Overholser; Kevin M Sowinski; Mark D Fisch; Jo E Rodgers; Ahmed Aldemerdash; Chia-Chi Hsu; Nan Wang; Elena Tomaselli Muensterman; Vijay U Rao; Richard J Kovacs Journal: J Card Fail Date: 2020-06-24 Impact factor: 5.712
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