Reduced Heart Rate Variability and Altered Cardiac Conduction after Pre-Eclampsia

Pre-eclampsia and long-term risk of arrhythmias

AIMS

Pre-eclampsia (PE), a pregnancy-induced hypertensive disorder, affects 4-5% of pregnancies worldwide. It is well known that hypertension is associated with an increased risk of arrhythmias; however, data on the association between PE and arrhythmias are sparse.

METHODS AND RESULTS

In this observational cohort study, we identified all primiparous women who gave birth in Denmark (1997-2016) using Danish nationwide registries. The women were stratified on whether they developed PE during primiparous pregnancy and followed from primiparous pregnancy to incident arrhythmia, emigration, death, or end of study (31 December 2018). A total of 523 271 primiparous women with a median age of 28 years were included, and 23 367 (4.5%) were diagnosed with PE. During a median follow-up of 10.1 years, women with and without PE were associated with a higher incidence of arrhythmias (1.42 vs. 1.02%): (i) composite of cardiac arrest, ventricular tachycardia/fibrillation, or implantable cardioverter defibrillator implantation [adjusted hazard ratio (HR) 1.60, 95% confidence interval (CI) 1.14-2.24], (ii) composite of advanced second- or third-degree atrioventricular block, sinoatrial dysfunction, or pacemaker implantation [adjusted HR 1.48 (95% CI 0.97-2.23)], (iii) composite of supraventricular tachyarrhythmias or extra systoles [adjusted HR 1.34 (95% CI 1.19-1.51)], and (iv) composite of all the above-mentioned arrhythmias [adjusted HR 1.37 (95% CI 1.23-1.54)].

CONCLUSION

Pre-eclamptic women were associated with a significantly and at hitherto unknown long-term increased rate of arrhythmias. This finding suggests that women with PE may benefit from cardiovascular risk assessment, screening, and preventive education.

The Role of Helicobacter pylori and Metabolic Syndrome-Related Mast Cell Activation Pathologies and Their Potential Impact on Pregnancy and Neonatal Outcomes

Helicobacter pylori infection, a significant global burden beyond the gastrointestinal tract, has long been implicated in various systemic pathologies. Rising evidence suggests that the bacterium's intricate relationship with the immune system and its potential to induce chronic inflammation impact diverse pathophysiological processes in pregnant women that may in turn affect the incidence of several adverse pregnancy and neonate outcomes. Helicobacter pylori infection, which has been linked to metabolic syndrome and other disorders by provoking pericyte dysfunction, hyperhomocysteinemia, galectin-3, atrial fibrillation, gut dysbiosis, and mast cell activation pathologies, may also contribute to adverse pregnancy and neonatal outcomes. Together with increasing our biological understanding of the individual and collective involvement of Helicobacter pylori infection-related metabolic syndrome and concurrent activation of mast cells in maternal, fetus, and neonatal health outcomes, the present narrative review may foster related research endeavors to offer novel therapeutic approaches and informed clinical practice interventions to mitigate relevant risks of this critical topic among pregnant women and their offspring.

Effect of Exercise Modality on Heart Rate Variability in Adults: A Systematic Review and Network Meta-Analysis

Background

The purpose of this study was to use a network meta-analysis (NMA) to compare the effects of aerobic training (AT), resistance training (RT), combined training (CBT), and high-intensity interval training (HIIT) on adult heart rate variability (HRV).

Methods

We searched PubMed, the Cochrane Library, Embase, the Web of Science, Wanfang Data, and the China National Knowledge Infrastructure to identify randomized controlled trials on the effects of exercise on HRV in adults. The search was conducted from the outset of these databases to April 2023. Two reviewers independently screened the retrieved articles, extracted raw data from the relevant studies, and assessed the possible risk of bias in the included studies.

Results

The NMA showed that HIIT had the greatest effect on the low-frequency (LF) power/high-frequency (HF) power ratio, standard deviation of normal-normal intervals (SDNN), and root mean square of successive differences between adjacent normal-to-normal intervals (RMSSD) (surface under the cumulative ranking curve (SUCRA) = 99.75%, 98.7%, and 84.9%); CBT had the greatest effect on the LF power (SUCRA = 66.3%); RT had the greatest effect on the HF power (SUCRA = 72.5%).

Conclusions

Our NMA and SUCRA ranking results suggest that in adults, HIIT is the most effective exercise modality in improving the SDNN, RMSSD, and LF/HF power ratio; RT for the HF power; CBT for the LF power. Any NMA conducted in the future must fully explore the effects of different exercise modalities on HRV in adult subgroups of different ages and genders.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=424054, identifier: CRD42023424054.

Maternal Cardiovascular Responses to Position Change in Pregnancy

The maternal cardiovascular-circulatory system undergoes profound changes almost from the conception of a pregnancy until the postpartum period to support the maternal adaptions required for pregnancy and lactation. Maintenance of cardiovascular homeostasis requires changes in the cardiovascular autonomic responses. Here, we present a longitudinal study of the maternal cardiovascular autonomic responses to pregnancy and maternal position. Over a normal gestation, in the left lateral position there are significant changes in both time and frequency domain parameters reflecting heart rate variability. We show that cardiovascular autonomic responses to physiological stressors (standing and supine positions in late pregnancy) became significantly different with advancing gestation. In the third trimester, 60% of the subjects had an unstable heart rate response on standing, and these subjects had a significantly reduced sample entropy evident in their heart rate variability data. By 6 weeks, postpartum function returned to near the non-pregnant state, but there were consistent differences in high-frequency power when compared to nulligravid cases. Finally, we review complementary evidence, in particular from magnetic resonance imaging, that provides insights into the maternal and fetal impacts of positioning in pregnancy. This demonstrates a clear relationship between supine position and maternal hemodynamic parameters, which relates to compression of the inferior vena cava (p = 0.05). Together, these studies demonstrate new understanding of the physiology of physiological stressors related to position.

Maternal heart rate variability patterns associated with maternal hypotension and non-reassuring fetal heart rate patterns following initiation of combined spinal-epidural labor analgesia: a prospective observational trial

BACKGROUND

We evaluated whether baseline maternal heart rate variability (HRV), including the Analgesia Nociception Index (ANI), is associated with maternal hypotension and fetal heart rate (FHR) abnormalities following combined spinal-epidural (CSE) labor analgesia.

METHODS

Laboring women were enrolled in this prospective observational study. The primary endpoint was maternal hypotension. The secondary endpoint was FHR abnormalities within 30 min following CSE analgesia initiated with intrathecal plain bupivacaine 1.0 mg and fentanyl 20 µg. The maternal ANI, electrocardiogram, blood pressure, heart rate, oxygen saturation, and FHR tracings were recorded 15 min before and 30 min after CSE. Parturients were grouped based on presence of hypotension and FHR abnormalities. Patient demographics and HRV metrics were compared. Receiver operating characteristics (ROC) curves were constructed for the prediction of hypotension and FHR abnormalities.

RESULTS

No significant intergroup differences were detected in patient characteristics. Several baseline HRV metrics and ANI differed significantly between the normotensive (n = 50) and hypotensive (n = 31) groups and between parturients showing FHR abnormalities (n = 19) and those showing reassuring FHR traces (n = 62). The area under the ROC curve (AUC) for predicting hypotension of the baseline low-frequency (LF)/high-frequency (HF) ratio was 0.677 (95% CI 0.55 to 0.80), and that of the ANI was 0.858 (95% CI 0.78 to 0.94). For predicting non-reassuring FHR patterns, the AUC of the LF/HF ratio was 0.77 (95% CI 0.65 to 0.89), and that of the ANI was 0.833 (95% CI 0.72 to 0.94).

CONCLUSIONS

The ANI can predict the propensity for maternal hypotension and non-reassuring FHR patterns following CSE.

Pregnancy-Related Complications and Incidence of Atrial Fibrillation: A Systematic Review

Pregnancy-related complications are associated with a higher risk of various incident cardiovascular diseases, but their specific potential relationship with incident atrial fibrillation (AF) is less clear. This systematic review summarises the available evidence from observational studies which have examined associations between pregnancy-related complications and the risk of AF. MEDLINE and EMBASE (Ovid) were searched for studies between 1990 to 10 February 2022. Pregnancy-related complications examined included hypertensive disorders of pregnancy (HDP), gestational diabetes, placental abruption, preterm birth, small-for-gestational-age and stillbirth. Study selection, data extraction and quality assessment were completed independently by two reviewers. Narrative synthesis was used to evaluate the results of the included studies. Nine observational studies were included, with eight eligible for narrative synthesis. Sample sizes ranged from 1839 to 2,359,386. Median follow-up ranged from 2 to 36 years. Six studies reported that pregnancy-related complications were associated with a significantly increased risk of incident AF. Hazard ratios (HRs) (95% confidence intervals) for the four studies that evaluated HDP ranged from 1.1 (0.8-1.6) to 1.9 (1.4-2.7). For the four studies that evaluated pre-eclampsia, HRs ranged from 1.2 (0.9-1.6) to 1.9 (1.7-2.2). Current evidence from observational studies suggests pregnancy-related complications are associated with a significantly higher risk of incident AF. However, only a small number of studies examining each pregnancy-related complication were identified, and considerable statistical heterogeneity was observed. Further large-scale prospective studies are required to confirm the association between pregnancy-related complications and incident AF.

CARDIOVASCULAR RISK IN WOMEN WITH PREECLAMPSIA

In this study, possible biochemical and functional cardiovascular markers were assessed in women with preeclampsia. Fifty-five pregnant women with manifest moderate (mild) preeclampsia (PE) and fifty healthy women as a control group were included in this prospective study. Laboratory tests including lipid panel, C-reactive protein (CRP), and homocysteine levels as biohumoral markers of atherogenesis, as well as ergometry and the main cardiovascular risk factor markers were performed in all women during pregnancy and six months after delivery. In our study, cholesterol and LDL levels in the PE group did not differ from those in the control group. Triglyceride levels in the PE group were higher than the corresponding values found in normal pregnancies, while HDL levels were significantly lower in the PE group than in the normal pregnancy group (p<0.001). The values of total cholesterol, LDL, HDL, and triglycerides in the PE group were higher compared to those in the same group six months after delivery (p<0.001). The effect of PE as an inflammatory disease could be confirmed to a certain extent by elevated CRP levels (p<0.001). A very high percentage of negative exercise stress tests indicated a good cardiovascular response to the current PE in the otherwise healthy pregestational women. It could be concluded that the development of possible cardiovascular comorbidities in preeclamptic pregnant women is a long process, but also due to etiologic factors of coexistent metabolic disorders such as dyslipidemia, as well as elevated inflammatory markers and homocysteine, PE can be considered even an early predictor of cardiovascular disease.

Maternal Cardiovascular Function Following a Pregnancy Complicated by Preeclampsia

Preeclampsia is a hypertensive pregnancy complication with an unknown etiology and high maternal burden worldwide. Burgeoning research has linked preeclampsia to adverse maternal health outcomes remote from pregnancy; however, the intermediary mechanisms responsible for this association have not been sufficiently established. In the present narrative review, we summarize leading evidence of structural and functional cardiovascular changes associated with prior preeclampsia, and how these changes may be linked to future maternal disease. KEY POINTS: · Prior preeclampsia is associated with subclinical structural and functional vascular changes remote from pregnancy.. · Maternal cardiac adaptations to preeclampsia may have long-term implications on cardiovascular health.. · Clinicians have an opportunity to minimize maternal disease risk following preeclampsia..

Increased Cardiac Arrhythmia After Pregnancy-Induced Hypertension: A South Korean Nationwide Database Study

Background

Although pregnancy‐induced hypertension (PIH) is associated with an elevated cardiovascular risk, long‐term studies or prepregnancy baseline data are scarce. Therefore, using a large nationwide cohort with prepregnancy periodic health screening data, we investigated whether clinically significant arrhythmia incidence increases after PIH.

Methods and Results

Data were extracted from the Korea National Health Insurance database and combined with the National Health Screening Examination database; women who gave birth between 2007 and 2015 and underwent the national health screening test within a year before pregnancy were followed up until 2016. We excluded women who had a diagnosis of arrhythmia within 1 year before pregnancy. The primary outcome was significant arrhythmia during the year after delivery. Secondary analysis included only specific diagnostic codes of arrhythmia with clinical significance. Additionally, the risk of arrhythmia was stratified by the use of magnesium sulfate. Of 2 035 684 women (PIH; n=37 297 versus normotensive pregnancy; n=1 998 387), the PIH group had a higher prepregnancy risk profile and showed a higher incidence of arrhythmia than women with normotensive pregnancies within 1 year. Women with PIH had a significantly higher risk of atrial flutter/fibrillation and atrioventricular block, but not lethal arrhythmias. Other predictors of arrhythmia development included advanced maternal age and cesarean section. Stratified analysis showed a higher risk of arrhythmia with magnesium sulfate use.

Conclusions

PIH was significantly associated with the development of arrhythmia within 1 year after delivery. Nevertheless, the incidence of lethal arrhythmias was not increased by PIH. Arrhythmia, especially atrial fibrillation, may largely contribute to increasing the future cardiovascular risk in women with a PIH history.

Cesarean delivery is associated with suppressed activities of the stress axes

Maternal pre- and post-delivery stress levels might be different for vaginal or cesarean deliveries. This study aimed to investigate the effects of type of delivery (vaginal or cesarean) and time of delivery (pre- and post-delivery) on the stress axes of the body, namely the hypothalamic-pituitary adrenal axis (HPA) and autonomic nervous system (ANS).Ninety-one pregnant women were volunteered to participate this prospective study. In these women, pre- and post-delivery HPA and ANS activities were measured noninvasively by salivary cortisol and heart rate variability (HRV), respectively. HRV was measured by 5-min electrocardiogram recording and time- and frequency-domain parameters were computed.Salivary cortisol concentration and HRV parameters were higher in women having vaginal delivery than those having cesarean delivery (p < 0.05). Cortisol levels did not differ between pre- and post-delivery (p > 0.05) but the time-domain parameters of HRV decreased post-delivery (p < 0.05). No interactions were observed between the types and times of delivery (p > 0.05).HPA and ANS axes had different activity patterns throughout the delivery process and they were higher during vaginal delivery, suggesting that they are integral parts of normal birth process and that cesarean delivery perturbs the activity of both axes.

Severe Preeclampsia is Associated with Functional and Structural Cardiac Alterations: A Case-control Study

BACKGROUND

The aim of the current study is to compare electrocardiographic and echocardiographic changes in patients with severe preeclampsia (PE) and those with uncomplicated pregnancies.

METHODS

This is a case-controlled prospective study consisting of 21 pregnant women with severe preeclampsia and a control group consisting of age- and gestational age-matched 24 healthy pregnant women. All patients underwent electrocardiographic and echocardiographic investigation.

RESULTS

QRS intervals were shorter and PR intervals were longer in the PE group (QRS duration: 80 (60-120) ms and 80 (40-110) ms, p=0.035; PR duration: 160 (100-240) ms and 120 (80-200) ms, respectively; p=0.046). The left ventricular end-systolic diameters of the patients with severe PE group were significantly larger than the control group (31 (24-36) mm and 30 (24-33) mm, respectively; p=0.05). Similarly, posterior wall thickness values of the PE group were significantly higher compared to the control group (9 (7-11) mm vs. 8 (6-10) mm, respectively; p=0.020). Left ventricular mass (146.63±27.73 g and 128.69±23.25 g, respectively; p=0.033) and relative wall thickness values (0.385±0.054 and 0.349±0.046, respectively; p=0.030) were also higher in the PE group. In addition, patients with early-onset severe PE had significantly a higher left ventricular end-diastolic diameter and volume compared with late-onset PE patients.

CONCLUSIONS

The structural changes detected in the severe PE group suggest a chronic process rather than an acute effect. In addition, diastolic dysfunction and left ventricular remodeling are most marked in patients with severe early-onset PE.

Heart rate variability in hypertensive pregnancy disorders: A systematic review

BACKGROUND

Hypertensive pregnancy disorders (HPD) are associated with dysfunction of the autonomic nervous system. Cardiac autonomic functions can be assessed by heart rate variability (HRV) measurements.

OBJECTIVE

To study whether HRV detects differences in the function of the autonomic nervous system between pregnant women with HPD compared to normotensive pregnant women and between women with a history of a pregnancy complicated by HPD compared to women with a history of an uncomplicated pregnancy.

METHODS

A systematic search was performed in Medline, EMBASE, and CENTRAL to identify studies comparing HRV between pregnant women with HPD or women with a history of HPD to women with (a history of) normotensive pregnancies.

RESULTS

The search identified 523 articles of which 24 were included in this review, including 850 women with (a history of) HPD and 1205 normotensive controls. The included studies showed a large heterogenicity. A decrease in overall HRV was found in preeclampsia (PE), compared to normotensive pregnant controls. A trend is seen towards increased low frequency/high frequency-ratio in women with PE compared to normotensive pregnant controls.

CONCLUSION

Our systematic review supports the hypothesis a sympathetic overdrive is found in HPD which is associated with a parasympathetic withdrawal. However, the included studies in our review showed a large diversity in the methods applied and their results.

Maternal Cardiac Function after Normal Delivery, Preeclampsia, and Eclampsia: A Prospective Study

Introduction

The aim of this study is to assess maternal cardiac function in the postpartum period, after 2 and 6 months in the parturient with preeclampsia and eclampsia.

Materials and Methods

Prospective study: 90 postpartum women after preeclampsia and eclampsia and 55 patients after an uncomplicated pregnancy. The parameters of maternal hemodynamics were recorded on days 1, 3, 5, 9, and 14 of postpartum period, after 2 and 6 months. The cardiac parameters were assessed.

Results

PE is accompanied by increased peripheral vascular resistance. The indicator of vascular resistance, SVR, is elevated for both mild and severe PE. With mild PE, a significant increase in SVR is observed up to 5 days of postpartum period, with severe PE/E up to 9 days. We found that in case of severe PE, SVR remains elevated to 6 months after delivery. The parameters of the contractile function of the heart (ESV, EDV, SV, SI, CO, СI, MVCF) were significantly decreased: with mild PE up to 5-9 days, with severe up to 9-14 days of puerperia. ESV, SV, SI, CO, and CI remain low with severe PE up to 6 months. The revealed decreasing of contractile function of the heart is a sign of asymptomatic heart failure.

Conclusions

The hemodynamics of the puerperas after PE and E is characterized by impaired contractility of the myocardium and an increase in the indices of peripheral resistance. The degree of deviation in the parameters of cardiac hemodynamics and vascular resistance depended on the severity of hypertensive complications of pregnancy.

Maternal heart rate patterns under resting conditions in late pregnancy

Objectives:

To describe maternal heart rate patterns observed during antenatal monitoring under resting conditions between the gestational ages of 34 to 38 weeks and to demonstrate its associations with uterine activity.

Methods:

Each participant had five high quality ECG electrodes attached to her anterior abdominal wall which were connected to the Monica AN24 device to collect raw electrical signals from the maternal and fetal ECG and signals of uterine activity. Proprietary software was then used to download the raw data and extract the maternal and fetal heart rate patterns and uterine activity.

Results:

Several distinct maternal heart rate patterns were observed. These included unusually high or low levels of variability, tachycardia, bradycardia, regular and irregular periodic changes and sporadic changes where the heart rate suddenly decreased or increased. Some of the fluctuations, especially decelerations of maternal heart rate, seemed to be associated with uterine activity.

Conclusion:

The clinical implications of these different patterns, for both the mother and fetus, needs to be explored further. There is a need for computerized analyses of the different maternal patterns during different gestational ages to determine its relevance.

Synopsis

Various maternal heart rate patterns under resting conditions in late pregnancy are described.

Maternal cardiovascular and endothelial function from first trimester to postpartum

Objective

To explore noninvasively the complex interactions of the maternal hemodynamic system throughout pregnancy and the resulting after-effect six weeks postpartum.

Methods

Eighteen women were tested beginning at the 12^th week of gestation at six time-points throughout pregnancy and six weeks postpartum. Heart rate, heart rate variability, blood pressure, pulse transit time (PTT), respiration, and baroreceptor sensitivity were analyzed in resting conditions. Additionally, hemoglobin, asymmetric and symmetric dimethylarginine and Endothelin (ET-1) were obtained.

Results

Heart rate and sympathovagal balance favoring sympathetic drive increased, the vagal tone and the baroreflex sensitivity decreased during pregnancy. Relative sympathetic drive (sympathovagal balance) reached a maximum at 6 weeks postpartum whereas the other variables did not differ compared to first trimester levels. Postpartum diastolic blood pressure was higher compared to first and second trimester. Pulse transit time and endothelial markers showed no difference throughout gestation. However, opposing variables PTT and asymmetric dimethylarginine (ADMA) were both higher six weeks postpartum.

Conclusions

The sympathetic up regulation throughout pregnancy goes hand in hand with a decreased baroreflex sensitivity. In the postpartum period, the autonomic nervous system, biochemical endothelial reactions and PTT show significant and opposing changes compared to pregnancy findings, indicating the complex aftermath of the increase of blood volume, the changes in perfusion strategies and blood pressure regulation that occur in pregnancy.

Hormones and sex differences: changes in cardiac electrophysiology with pregnancy

Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.

Long-term cerebral white and gray matter changes after preeclampsia

Objective:

To determine whether changes in cerebral structure are present after preeclampsia that may explain increased cerebrovascular risk in these women.

Methods:

We conducted a case control study in women between 5 and 15 years after either a preeclamptic or normotensive pregnancy. Brain MRI was performed. Analysis of white matter structure was undertaken using voxel-based segmentation of fluid-attenuation inversion recovery sequences to assess white matter lesion volume and diffusion tensor imaging to measure microstructural integrity. Voxel-based analysis of gray matter volumes was performed with adjustment for skull size.

Results:

Thirty-four previously preeclamptic women (aged 42.8 ± 5.1 years) and 49 controls were included. Previously preeclamptic women had reduced cortical gray matter volume (523.2 ± 30.1 vs 544.4 ± 44.7 mL, p < 0.05) and, although both groups displayed white matter lesions, changes were more extensive in previously preeclamptic women. They displayed increased temporal lobe white matter disease (lesion volume: 23.2 ± 24.9 vs 10.9 ± 15.0 μL, p < 0.05) and altered microstructural integrity (radial diffusivity: 538 ± 19 vs 526 ± 18 × 10⁻⁶ mm²/s, p < 0.01), which also extended to occipital and parietal lobes. The degree of temporal lobe white matter change in previously preeclamptic women was independent of their current cardiovascular risk profile (p < 0.05) and increased with time from index pregnancy (p < 0.05).

Conclusion:

A history of preeclampsia is associated with temporal lobe white matter changes and reduced cortical volume in young women, which is out of proportion to their classic cardiovascular risk profile. The severity of changes is proportional to time since pregnancy, which would be consistent with continued accumulation of damage after pregnancy.

Heart Rate Variability and Autonomic Modulations in Preeclampsia

Background

Although the exact pathophysiology of preeclampsia is not well understood, autonomic nervous system imbalance is suggested as one of the main factors.

Aims

To investigate heart rate variability (HRV) and autonomic modulations in Sudanese pregnant women with preeclampsia.

Subjects and Methods

A case-control study (60 women in each arm) was conducted at Omdurman Maternity Hospital—Sudan, during the period from June to August, 2014. Cases were women presented with preeclampsia and healthy pregnant women were the controls. Studied groups were matched for important determinants of HRV. Natural logarithm (Ln) of total power (TP), high frequency (HF), low frequency (LF) and very low frequency (VLF) were used to determine HRV. Normalized low and high frequencies (LF Norm and HF Norm) were used to evaluate sympathetic and parasympathetic autonomic modulations respectively.

Results

Patients with preeclampsia achieved significantly higher LF Norm [49.80 (16.25) vs. 44.55 (19.15), P = 0.044] and LnLF/HF [0.04 (0.68) vs. -0.28 (0.91), P = 0.023] readings, but lower HF Norm [49.08 (15.29) vs. 55.87 (19.56), P = 0.012], compared with healthy pregnant women. Although all other HRV measurements were higher in the patients with preeclampsia compared with the controls, only LnVLF [4.50 (1.19) vs. 4.01 (1.06), P = 0.017] and LnLF [4.01 (1.58) vs. 3.49 (1.23), P = 0.040] reached statistical significance.

Conclusion

The study adds further evidence for the dominant cardiac sympathetic modulations on patients with preeclampsia, probably secondary to parasympathetic withdrawal in this group. However, the higher LnVLF and LnLF readings achieved by preeclamptic women compared with the controls are unexpected in the view that augmented sympathetic modulations usually depresses all HRV parameters including these two measures.