Heart Rate Variability and Autonomic Modulations in Preeclampsia

Area of Science:

• Cardiology
• Obstetrics
• Physiology

Background:

• Preeclampsia pathophysiology remains unclear, but autonomic nervous system imbalance is a suspected factor.
• Autonomic dysfunction may play a significant role in the development of preeclampsia.

Purpose of the Study:

• To investigate heart rate variability (HRV) and autonomic modulations in Sudanese pregnant women with preeclampsia.
• To compare HRV parameters between preeclamptic and healthy pregnant women.

Main Methods:

• A case-control study involving 120 Sudanese pregnant women (60 preeclampsia, 60 healthy controls).
• Heart rate variability (HRV) was assessed using natural logarithm (Ln) of total power (TP), high frequency (HF), low frequency (LF), and very low frequency (VLF).
• Autonomic modulations were evaluated using normalized low and high frequencies (LF Norm and HF Norm).

Main Results:

• Preeclamptic women showed significantly higher LF Norm and LnLF/HF ratios, indicating increased sympathetic activity.
• A lower HF Norm was observed in preeclamptic women, suggesting parasympathetic withdrawal.
• While most HRV measures were higher in preeclamptics, only LnVLF and LnLF reached statistical significance.

Conclusions:

• The study provides evidence for dominant cardiac sympathetic modulations in preeclampsia, likely due to parasympathetic withdrawal.
• Unexpectedly higher LnVLF and LnLF readings in preeclamptic women challenge typical findings of augmented sympathetic activity on HRV parameters.