|
|
||||||||
3 Department of Obstetrics and Gynaecology and 2 Department of Physiology, 1 School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada K7L 3N6
This study examined the effects of human pregnancy on heart rate variability (HRV), spontaneous baroreflex (SBR) sensitivity, and plasma catecholamines at rest and during exercise. Subjects were 14 healthy, physically active pregnant women (PG; mean gestational age = 33.9 ± 1.0 wk). Results were compared with an age-matched nonpregnant control group (NPG; n = 14) with similar characteristics. The electrocardiographic R-wave-R-wave interval and systolic blood pressure (via finger plethysmograph) were measured on a beat-to-beat basis at rest and during upright cycling at 60 and 110% of the ventilatory threshold (Tvent). Parasympathetic nervous system (PNS) modulation (as reflected by HRV high-frequency/total power and SBR slope) was significantly reduced at rest in the PG vs. the NPG. During exercise, PNS modulation decreased significantly in both groups, but the magnitude of PNS withdrawal from rest to 110% Tvent was smaller in the PG vs. NPG. Sympathetic nervous system (SNS) modulation (reflected by the low-frequency power-to-high-frequency power ratio) increased above resting values at 60 and 110% Tvent in the NPG. SNS modulation at 110% Tvent was significantly lower in the PG compared with the NPG. Plasma norepinephrine and epinephrine levels were also lower at 110% Tvent in the PG. It was concluded that healthy pregnant women exhibit lower PNS modulation at rest and blunted SNS modulation during exercise above Tvent in late gestation.
spectral analysis; spontaneous baroreflex function; human gestation; exercise intensity
This article has been cited by other articles:
![]() |
C. A. Brown, C. T. Lee, S. M. J. Hains, and B. S. Kisilevsky Maternal Heart Rate Variability and Fetal Behavior in Hypertensive and Normotensive Pregnancies Biol Res Nurs, October 1, 2008; 10(2): 134 - 144. [Abstract] [PDF] |
||||
![]() |
D. Jensen, K. A. Webb, G. A. L. Davies, and D. E. O'Donnell Mechanical ventilatory constraints during incremental cycle exercise in human pregnancy: implications for respiratory sensation J. Physiol., October 1, 2008; 586(19): 4735 - 4750. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Helmreich, V. Hundley, and P. Varvel The Effect of Obesity on Heart Rate (Heart Period) and Physiologic Parameters During Pregnancy Biol Res Nurs, July 1, 2008; 10(1): 63 - 78. [Abstract] [PDF] |
||||
![]() |
A. P. Heenan, L. A. Wolfe, G. A. L. Davies, and M. J. McGrath Effects of human pregnancy on fluid regulation responses to short-term exercise J Appl Physiol, December 1, 2003; 95(6): 2321 - 2327. [Abstract] [Full Text] |
||||
![]() |
K. P. O'Hagan and J. A. Alberts Uterine artery blood flow and renal sympathetic nerve activity during exercise in rabbit pregnancy Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2003; 285(5): R1135 - R1144. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |