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The effect of position on autonomic nervous activity in late pregnancy
Author(s) -
Kuo C.D.,
Chen G.Y.,
Yang M.J.,
Tsai Y.S.
Publication year - 1997
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.1997.254-az0387.x
Subject(s) - supine position , medicine , pregnancy , autonomic nervous system , heart rate variability , cardiology , heart rate , anesthesia , blood pressure , genetics , biology
We investigated the effect of three different recumbent positions on autonomic nervous activity in late pregnancy. Thirty pregnant and 24 nonpregnant aged‐matched women were studied, and measures of heart rate variability in both time and frequency domains were compared using supine, right and left lateral decubitus positions. In the nonpregnant women, the normalised high‐frequency power was greatest in the right lateral decubitus position. In the pregnant women, the normalised high‐frequency power was lowest and the low/high‐frequency power ratio was greatest in the supine position. Both the percentage decrease of normalised high‐frequency power and the percentage increase of low/high‐frequency power ratio in the supine and right lateral positions were greater than those in the left lateral position. For women in late pregnancy, the left lateral decubitus position may be beneficial because cardiac vagal activity is least suppressed and cardiac sympathetic activity is least enhanced. Aortocaval compression might be the mechanism underlying the change in cardiac autonomic nervous activity when supine and right lateral decubitus positions are assumed in late pregnancy.