Postpartum Blood Pressure Variability and Heart Rate Variability in Preeclampsia.

Abstract

BACKGROUND Preeclampsia is associated with autonomic dysregulation during pregnancy; however, less is known about autonomic function in the first week postpartum after preeclampsia. METHODS We retrospectively analyzed data from a prospective cohort of women with and without preeclampsia. Continuous blood pressure and heart rate were measured with finger plethysmography within 7 days postpartum. Frequency-domain blood pressure and heart rate variability (HRV) were calculated using spectral analysis. Time-domain HRV was calculated as the root mean square of successive RR interval differences. We compared results between those with and without preeclampsia, as well as between those with new-onset preeclampsia, chronic hypertension with superimposed preeclampsia, and normotensive participants. RESULTS A total of 70 postpartum women were enrolled: 20 normotensive, 29 new-onset preeclampsia, and 21 superimposed preeclampsia. Both low- and high-frequency blood pressure variabilities were higher in those with preeclampsia compared with controls (P=0.04 and P=0.02, respectively). This difference was driven by those with new-onset preeclampsia. The preeclampsia group had lower high-frequency HRV (P<0.005), a higher low-/high-frequency ratio of HRV (P<0.005), and lower time-domain HRV (P=0.01); this difference was seen in those with and without chronic hypertension. CONCLUSIONS Postpartum patients with preeclampsia with and without chronic hypertension had lower HRV compared with normotensive postpartum controls. Higher blood pressure variability was observed only in those with nonsuperimposed preeclampsia, suggesting that the autonomic profile of preeclampsia may differ in patients with chronic hypertension.