The impact of preeclampsia on fetal ECG morphology and heart rate variability

Abstract

The aim of the investigation was a survey of the fetal HRV and ECG parameters in preeclampsia. It was performed fetal noninvasive ECG recordings in 94 pregnant women at 34-41 weeks of gestation and 66 of them were preeclamptic patients. The fetal deterioration in preeclampsia was characterized by lowered fetal heart rate variability and all its fractal components. The autonomic tone was diminished in direct proportion to the severity degree of preeclampsia. The mean value of short term vagal mediated parameters: RMSSD (root mean square of successive differences), pNN50 (the proportion of the number of pairs of successive NNs that differ by more than 50 ms divided by total number of NNs), HF (high frequency) and STV (short term variability) was also decreased. The relative predominance of the central sympathetic baroreflex mediated regulation of fetal hemodynamic was the main event in the preeclampsia induced scenario. The increased value of AMo (the amplitude of mode) and SI (stress index) was associated with abnormal myocardial adrenergic stimulation. It has induced pQ and QT shortening, increased T/QRS ratio and decelerations appearance. The augmented sympathetic tone played the significant role in fetal rigid rhythm and decelerations appearance and has formed the fetal myocardium hypoxic injury and suppressed sinus node response.