| Title | Return of autonomic nervous activity after delivery: role of aortocaval compression. | ||
| Author | Chen, G Y; Kuo, C D; Yang, M J; Lo, H M; Tsai, Y S | ||
| Journal | Br J Anaesth | Publication Year/Month | 1999-Jun |
| PMID | 10562793 | PMCID | -N/A- |
| Affiliation | 1.Department of Medicine, Provincial Tao-Yuan General Hospital, Taiwan, Republic of China. | ||
We have compared measures of heart rate variability (HRV) in 15 women in late pregnancy before and 3 months after delivery and in 20 non-pregnant controls, to study the effect of aortocaval compression on autonomic nervous activity. Normalized high-frequency power was used as an index of vagal activity and the low-/high-frequency power ratio as index of sympathovagal balance. We found that the decrease in vagal activity and increase in sympathovagal balance before delivery returned to normal 3 months after delivery. Percentage changes in vagal activity and sympathovagal balance 3 months after delivery in the left lateral decubitus position were least among three recumbent positions. The relief of aortocaval compression as a result of delivery of the fetus may be the main cause of return of autonomic nervous activity 3 months after delivery. Postpartum hormonal changes may also contribute to return of autonomic nervous activity after delivery.