Cardiac Autonomic Balance is Impaired in Preeclampsia

Objective: Preeclampsia is characterized by marked increase in peripheral vascular resistance resulting in high arterial blood pressure and proteinuria in pregnancy. Autonomic imbalance may play a role in the pathogenesis of preeclampsia. Our aim was to investigate the cardiac autonomic status in preeclampsia by using heart rate variability (HRV). Material and Methods: Age- and gestational age-matched subjects consisting of 34 pregnant women with preeclampsia and 29 healthy pregnant women were enrolled in the study. In order to rule out the effect of any medication and concomitant disease all participants were selected among these without any medication at that time and underwent a detailed physical examination and blood chemistry analysis. Analysis of HRV was performed in all subjects from 24-hr Holter recording data. Preeclampsia was defined as diastolic blood pressure over 90 mmHg in previously normotensive woman, and proteinuria over 300 mg/day. Results: In preeclamptic pregnant women, the HRV indices that reflect both parasympathetic activity and global autonomic functions were lower than in healthy pregnants. Conclusion: Although it was speculated that low circulating volume causes direct baroreflex-mediated stimulation of the sympathetic system resulting with high vascular resistance in preeclamptic patients, our results imply that alteration in central regulation mechanisms may have a role in autonomic imbalance in preeclamptic women.