In late pregnancy, the left lateral decubitus position minimizes suppression of cardiac vagal activity and enhancement of cardiac sympathetic activity compared to supine and right lateral positions.
Cross-Sectional (n=54)
Does recumbent position affect cardiac autonomic nervous activity and heart rate variability in women in late pregnancy?
The left lateral decubitus position in late pregnancy minimizes the suppression of cardiac vagal activity and enhancement of sympathetic activity compared to supine or right lateral positions, likely by reducing aortocaval compression.
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.
Kuo et al. (Mon,) conducted a cross-sectional in Late pregnancy (n=54). Recumbent positions (supine, right and left lateral decubitus) vs. Different positions compared within subjects was evaluated on Heart rate variability (normalised high-frequency power and low/high-frequency power ratio). In late pregnancy, the left lateral decubitus position minimizes suppression of cardiac vagal activity and enhancement of cardiac sympathetic activity compared to supine and right lateral positions.