title: Changes in resting heart rate variability across the menstrual cycle.
abstract: Heart rate variability (HRV) is a noninvasive indicator of autonomic control. This study examines HRV changes across a normal menstrual cycle and proposes a novel piecewise function controlling for the effects of breathing on HRV spectral parameters. A resting ECG was collected from 13 women at five points in their menstrual cycle. Both heart rate and breathing rate increased across the cycle (p < .01) while time-domain variability decreased (p = .04). Use of the piecewise function for breathing rate in HRV spectral analysis was confirmed by a substantial increase in model goodness-of-fit. HRV spectral parameters, controlled for breathing with the piecewise function, confirm that the decrease in variability is likely due to a parasympathetic withdrawal, since high frequency HRV decreases (p = .02).
authors.affiliation: Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas, USA; United States Army Research Laboratory-Human Research and Engineering Directorate, Aberdeen Proving Ground, Maryland, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Tenan
authors.forename: R Matthew
authors.initials: RM
authors.lastname: Brothers
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Tweedell
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Hackney
authors.forename: Lisa
authors.initials: L
authors.lastname: Griffin
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D056152:Respiratory Rate / Q000502:physiology; D055815:Young Adult
keywords: Autonomic nervous system; Estrogen; Heart rate variability; Menstrual cycle; Progesterone