Heart rate variability and the risk of heart failure and its subtypes in post-menopausal women: The Women's Health Initiative study

Is cardiovascular disease risk in transgender, gender-diverse, and non-binary adults associated with autonomic imbalance?

Blood pressure is a key indicator of cardiovascular health with chronically high levels increasing the risk of cardiovascular diseases (CVD) such as heart attack and stroke. Emerging evidence shows that transgender, gender-diverse, and non-binary (TGD) adults tend to have higher blood pressure than age-matched cisgender adults, corresponding to an increased CVD risk in this population. Yet, the mechanisms underlying elevated blood pressure in TGD adults remain unclear, posing challenges to TGD-affirming healthcare. Given the autonomic nervous system's role in CVD - wherein reduced parasympathetic and heightened sympathetic activity are key risk factors for CVD - this review explores the question: "Is cardiovascular disease risk in TGD adults associated with autonomic imbalance?" Limited research exists on autonomic balance within TGD populations. Accordingly, this review considers how TGD-specific factors, such as minority stress, lifestyle behaviors, sex and gender, and hormones (i.e., testosterone, estrogen, progesterone), may impact autonomic balance. Finally, this review aims to underscore the critical need for interdisciplinary research to elucidate these mechanisms and advance TGD-inclusive healthcare in the domains of autonomic control of blood pressure and overall cardiovascular health.

Heart Rate Variability Applications in Medical Specialties: A Narrative Review

HRV is clinically considered to be a surrogate measure of the asymmetrical interplay of the sympathetic and parasympathetic nervous system. While HRV has become an increasingly measured variable through commercially-available wearable devices, HRV is not routinely monitored or utilized in healthcare settings at this time. The purpose of this narrative review is to discuss and evaluate the current research and potential future applications of HRV in several medical specialties, including critical care, cardiology, pulmonology, nephrology, gastroenterology, endocrinology, infectious disease, hematology and oncology, neurology and rehabilitation, sports medicine, surgery and anesthesiology, rheumatology and chronic pain, obstetrics and gynecology, pediatrics, and psychiatry/psychology. A narrative literature review was conducted with search terms including HRV and relevant terminology to the medical specialty in question. While HRV has demonstrated promise for some diagnoses as a non-invasive, easy to use, and cost-effective metric for early disease detection, prognosis and mortality prediction, disease monitoring, and biofeedback therapy, several issues plague the current literature. Substantial heterogeneity exists in the current HRV literature which limits its applicability in clinical practice. However, applications of HRV in psychiatry, critical care, and in specific chronic diseases demonstrate sufficient evidence to warrant clinical application regardless of the surmountable research issues. More data is needed to understand the exact impact of standardizing HRV monitoring and treatment protocols on patient outcomes in each of the clinical contexts discussed in this paper.

Vagal Nerve Biofeedback Intervention for Improving Health Outcomes Among Ukrainian Forced Migrants: A Proof-of-Concept Study

BACKGROUND

The ongoing conflict in Ukraine has forced numerous migrants into neighboring countries, many suffering from pre-existing or newly acquired physical and mental health conditions. Addressing these complex challenges in humanitarian settings requires innovative, evidence-based interventions that are cost-effective and easy to administer. Drawing upon research highlighting the vagus nerve's role in regulating well-being, we hypothesized that vagal nerve activation could offer a promising therapeutic approach.

METHOD

We conducted a proof-of-concept study in which 21 Ukrainian forced migrants were trained in a biofeedback-guided paced breathing intervention designed to stimulate the vagus nerve and promote self-regulation of stress response systems. Changes in pain perception, perceived stress, blood pressure, and heart rate were assessed before and after the vagal breathing intervention using a t-test. Correlations were examined at baseline.

RESULTS

Statistically significant improvements were observed in all measures except systolic blood pressure, providing preliminary evidence for the efficacy of vagal nerve activation in alleviating stress-related health symptoms.

CONCLUSIONS

This study demonstrates the feasibility and therapeutic potential of a vagal nerve-activating intervention in a humanitarian setting. These findings warrant replication in larger, controlled trials. If substantiated, this low-cost, scalable intervention could help mitigate health burdens among forced migrant populations worldwide.

The Mechanism by Which Estrogen Level Affects Knee Osteoarthritis Pain in Perimenopause and Non-Pharmacological Measures

Perimenopausal women have fluctuating estrogen levels, which often trigger a range of symptoms of perimenopausal syndromes as estrogen levels decrease. Changes in perimenopausal estrogen levels are closely related to pain in knee osteoarthritis (KOA), which has long been a research area of great interest in perimenopausal women. In recent years, it has been found that perimenopausal estrogen levels have an important role in KOA pain, namely, that estrogen can affect KOA pain through the regulation of inflammatory responses, inhibition of cellular senescence and apoptosis, and modulation of neurotransmitters, which may provide new ideas for KOA treatment. This study aims to describe the mechanism of estrogen level on knee osteoarthritis pain in perimenopause and related non-pharmacological measures, such as physical therapy, physical factor therapy, traditional Chinese medicine, and diet, which can provide a reference for the study and treatment of pain in perimenopausal women with KOA.

Listening to a Three-Dimensional Virtual Reality Sound: Effects on Stress Response of Adults

INTRODUCTION

Virtual reality (VR) technologies utilizing three-dimensional (3D) sound may offer sensually engaging imitations. Thus, they may lead to relaxation or may provide a way of escaping from disturbing life events. As they have the potential to manage stress, the current study aimed to investigate the effects of VR 3D sounds on the stress axes of the body, namely the autonomic nervous system (ANS) and hypothalamo-pituitary-adrenal (HPA).

METHODS

Participants (19 men and 27 women, mean age 25.8 ± 10.4 years), wearing on-ear headphones, did not listen to anything (control) or listened to a mono or 3D sound imitating a real-life situation taking place in a virtual barbershop. The control phase was immediately followed by mono or 3D phases. Half of the participants in mono and 3D phases were crossed, with 45 min intervals, to control the effect of time and habituation. Reactivity of ANS and HPA was measured by heart rate variability (HRV) and salivary cortisol measurements, respectively. HRV was measured during each phase by a 5-min continuous electrocardiogram recording. Salivary samples were taken during control recording and 15-min after mono or 3D sound listening. HRV parameters consisted of both time- and frequency-domain parameters, including standard deviation of R-R interval (SDNN), total power (TP), and low frequency/high frequency (LF/HF), as a measure for sympathovagal activity.

RESULTS

Compared to the control phase, the 3D sound increased almost all HRV parameters (including SDNN, TP, LF/HF, etc., p < 0.05) but did not affect salivary cortisol levels (p > 0.05). Effects of mono sound were in between the control and 3D sound phases.

CONCLUSION

It seems that a 3D sound imitating a real-life environment does not affect HPA but increases HRV and sympathovagal balance, suggesting that VR 3D sound is likely to reproduce an ANS response observed in real life.

Test-Retest Reliability and Concurrent Validity of Photoplethysmography Finger Sensor to Collect Measures of Heart Rate Variability

The purpose of the current study was to determine the test-retest reliability and concurrent validity of a photoplethysmography (PPG) finger sensor when collecting heart rate variability (HRV) metrics in reference to electrocardiography (ECG) and heart rate monitor (HRM) devices. Five minutes of R-R interval data were collected from 45 participants (23 females; age: 23.13 ± 4.45 yrs; body mass index: 25.39 ± 4.13 kg/m2) in the supine and seated positions in testing sessions 48 h apart. Moderate-to-excellent test-retest reliability of the HRV data collected from the PPG sensor was identified (ICC2,1 = 0.60-0.93). Additionally, similar standard errors of the mean, coefficient of variation, and minimal detectable change metrics were observed across all devices. Statistically significant (p < 0.05) differences were identified in the HRV data between the PPG sensor and ECG and HRM devices; however, these differences were interpreted as trivial-to-small (g = 0.00-0.59). Further, the PPG sensor tended to only overestimate HRV metrics by <0.5 ms and near perfect relationships (r = 0.91-1.00) and very large-to-near perfect agreement (CCC = 0.81-1.00) were identified between collection methods. The PPG sensor demonstrated adequate test-retest reliability and concurrent validity in both the supine and seated resting positions.

Renal Denervation in Heart Failure Treatment: Data for a Self-Fulfilling Prophecy

Renal denervation (RDN), a transcatheter renal sympathetic nerve ablation procedure, is a relatively novel established procedure for the treatment of hypertension, with it being recognized as a third option for hypertension management in the most recent European guidelines, together with pharmacotherapy, for achieving blood pressure targets. Given the relationship between both hypertension and sympathetic overdrive and the development of heart failure (HF), even studies at the dawn of research on RDN explored it as a treatment to overcome diuretic resistance in those patients. As it is now recognized that RDN does not only have organ-specific but also systemic effects, several investigators have aimed to delineate whether renal sympathetic denervation could alter the prognosis, symptoms, and adverse events of HF patients. Data are available in both HF patients with reduced and preserved ejection fraction. As the significance of neuromodulation is gaining grounds in the HF therapeutic arsenal, in this review, we aim to provide a rationale for using RDN in HF and an up-to-date overview of available data in both HF phenotypes, as well as discuss the future of neuromodulatory therapy in HF management.

Evaluation of Pro-BNP biomarker in heart failure patients and its relationship with complete blood count parameters: A case-control study

Background and aims

Heart failure (HF) is a growing global health concern. N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) is an established biomarker for ventricular dysfunction in heart failure (HF). This case-control study examined the relationship between brain natriuretic peptide (Pro-BNP) levels and complete blood count (CBC) parameters in HF patients and healthy controls, exploring the utility of CBC as a supplementary diagnostic tool for HF.

Methods

The study included 89 participants, divided into 42 HF patients with diagnosed HF (patient group) and 47 healthy individuals (control group). Pro-BNP levels were measured alongside a comprehensive CBC panel, including parameters such as white blood cell count, hemoglobin levels, and platelet count. Demographic, clinical characteristics, and CBC parameters were compared between the two groups, with statistical analyses performed to identify any significant associations.

Results

The analysis demonstrated that HF patients had significantly higher Pro-BNP levels than the control subjects, indicating a strong association between Pro-BNP levels and HF (1052.65 [196.56] vs. 2500.34 [1105.90], p < 0.001). Moreover, significant differences in CBC parameters, such as platelet count: 246.96 (82.72) versus 206.45 (57.20), p = 0.009; mean corpuscular volume (MCV): 83.74 (5.86) versus 87.12 (4.60), p < 0.00; and red cell distribution width: 13.47 (1.29) versus 14.28 (1.35), p < 0.001) were observed, with the patient group showing altered levels indicative of cardiac stress and inflammation. Correlation analysis further established the relationship between Pro-BNP levels and CBC parameters, with notable correlations observed with MCV (0.250, p < 0.020) and mean corpuscular hemoglobin levels (0.246, p < 0.045). These findings suggest a complex interplay between Pro-BNP levels and CBC parameters, underscoring the potential of CBC parameters as auxiliary diagnostic markers in HF.

Conclusion

Pro-BNP exhibits clinical relevance in diagnosing cardiovascular dysfunction, with elevated levels and distinct hematological profiles in HF patients. Pro-BNP's diagnostic and predictive capabilities for hematocrit and platelet count support its use in risk assessment and treatment decisions for HF.

Assessing Children's Autonomic Nervous System Activity During Structured Tasks: A Feasibility and Reliability Study in Ghana

The significance of physiological regulation in relation to behavioral and emotional regulation is well documented, but primarily in economically advantaged contexts. Few studies have been conducted in low- and middle-income countries. We investigated the feasibility and reliability of measuring autonomic nervous system (ANS) activity and behavior during challenge tasks in 30 children aged 8-10 years in Ghana during two visits, 1 week apart. Completeness of ANS data ranged from 80% to 100% across all tasks. There was low-to-moderate test-retest reliability of video mood induction (VMI) emotion ratings and balloon analog risk task (BART) pumps (r = 0.34-0.52). VMI elicited higher targeted emotion ratings in Visit 2 than Visit 1. Respiratory sinus arrhythmia (RSA) was higher, and pre-ejection period (PEP) was longer at Visit 2 than Visit 1 for baseline and both tasks. RSA was higher at baseline than during the VMI anger scene at Visit 1, whereas PEP was shorter at baseline than during all VMI emotion scenes at Visit 2. RSA was higher at baseline than during BART at both visits. In conclusion, ANS data collection within evocative and arousing challenge tasks was feasible in Ghana, and the tasks were generally reliable and effective in eliciting target emotions and risk-taking behavior in this sample.

Unheralded Adrenergic Receptor Signaling in Cellular Oxidative Stress and Death

Catecholamines (CAs) bind and activate adrenergic receptors (ARs), thus exuding a key role in cardiac adaptations to global physiological queues. Prolonged exposure to high levels of CAs promotes deleterious effects on the cardiovascular system, leading to organ dysfunction and heart failure (HF). In addition to the prominent role of ARs in inotropic and chronotropic responses, recent studies have delved into elucidating mechanisms contributing to CA toxicity and cell death. Central to this process is understanding the involvement of α1AR and βAR in cardiac remodeling and mechanisms of cellular survival. Here, we highlight the complexity of AR signaling and the fundamental need for a better understanding of its contribution to oxidative stress and cell death. This crucial informational nexus remains a barrier to the development of new therapeutic strategies for cardiovascular diseases.

Pregnancy, Reproductive Factors, and Female Heart Failure Risk and Outcomes

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of recent evidence on female-specific risk factors related to reproductive status or pregnancy.

RECENT FINDINGS

Pregnancy-related factors, including hypertensive disorders and gestational diabetes, increase the risk of heart failure in women, while breastfeeding and hormone therapy may offer protection. Hypertensive disorders of pregnancy, gestational diabetes, polycystic ovarian syndrome, placental abruption, younger maternal age at first live birth, younger maternal age at last live birth, number of stillbirths, number of pregnancies, onset of menstruation before 12 years of age, shorter reproductive age, ovariectomy, and prolonged absence of ovarian hormones may increase the risk of heart failure in women. Conversely, breastfeeding status and hormone therapy (for menopause or contraception) may serve as protective factors, while fertility treatments have no discernible effect on the risk of heart failure.

Regulation of exercise on heart rate variability in perimenopausal and postmenopausal women

Heart rate variability (HRV) is a non-invasive quantitative measure of cardiac autonomic nervous activity. Due to the increase of age and the decrease of estrogen level in perimenopausal and postmenopausal women, the cardiac autonomic nervous function is abnormal, increasing the risk of cardiovascular disease. Proper exercise can increase estrogen levels, improve cardiovascular health, regulate cardiac autonomic nervous activity, and reduce the risk of cardiovascular disease. Low-moderate intensity aerobic exercise, resistance exercise, aerobic combined resistance exercise and mind-body exercise have positive effects on HRV in perimenopausal and postmenopausal women. Therefore, summarizing the effects of different exercise modes on HRV in perimenopausal and postmenopausal women, as well as the mechanism of exercise training improvement on HRV, so as to adopt better exercise strategies to improve HRV of perimenopausal and postmenopausal women, and thus reduce the risk of cardiovascular diseases and improve the health level and quality of life of perimenopausal and postmenopausal women.

An association between heart rate variability and incident heart failure in an elderly cohort

BACKGROUND

Early identification of individuals at risk of developing heart failure (HF) may improve poor prognosis. A dominant sympathetic activity is common in HF and associated with worse outcomes; however, less is known about the autonomic balance before HF.

HYPOTHESIS

A low frequency/high frequency (L-F/H-F) ratio, index of heart rate variability, and marker of the autonomic balance predict the development of HF and may improve the performance of the HF prediction model when added to traditional cardiovascular (CV) risk factors.

METHODS

Individuals in the PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study (n = 1016, all aged 70 years) were included. Exclusion criteria were prevalent HF, electrocardiographic QRS duration ≥130 millisecond, major arrhythmias, or conduction blocks at baseline. The association between the L-F/H-F ratio and incident HF was assessed using Cox proportional hazard analysis. The C-statistic evaluated whether adding the L-F/H-F-ratio to traditional CV risk factors improved the discrimination of incident HF.

RESULTS

HF developed in 107/836 study participants during 15 years of follow-up. A nonlinear, inverse association between the L-F/H-F ratio and incident HF was mainly driven by an L-F/H-F ratio of <30. The association curve was flat for higher values (hazard ratio, HR for the total curve = 0.78 [95% confidence interval, CI: 0.69-0.88, p < .001]; HR = 2 for L-F/H-F ratio = 10). The traditional prediction model improved by 3.3% (p < .03) when the L-F/H-F ratio was added.

CONCLUSIONS

An L-F/H-F ratio of <30 was related to incident HF and improved HF prediction when added to traditional CV risk factors.

Heart rate variability and cardiovascular diseases: A Mendelian randomization study

BACKGROUND

The causal relationship between heart rate variability and cardiovascular diseases and the associated events is still unclear, and the conclusions of current studies are inconsistent. We aimed to explore the relationship between heart rate variability and cardiovascular diseases and the associated events with the Mendelian randomization study.

METHODS

We selected normal-to-normal inter-beat intervals (SDNN), root mean square of the successive differences of inter-beat intervals (RMSSD) and peak-valley respiratory sinus arrhythmia or high-frequency power (pvRSA/HF) as the three sets of instrumental variables for heart rate variability. The outcome for cardiovascular diseases included essential hypertension, heart failure, angina pectoris, myocardial infarction, nonischemic cardiomyopathy and arrhythmia. Cardiac arrest, cardiac death and major coronary heart disease event were defined as the related events of cardiovascular diseases. The data for exposures and outcomes were derived from publicly available genome-wide association studies. Inverse variance weighted was used for the main causal estimation. Analyses of heterogeneity and pleiotropy were conducted using the Cochran Q test of Inverse variance weighted and MR-Egger, leave-one-out analysis, and MR-Pleiotropy Residual Sum and Outlier methods.

RESULTS

The Inverse variance weighted method indicated that genetically predicted pvRSA/HF was associated with the increased risk of cardiac arrest (odds ratio 2.02, 95% confidence interval 1.25-3.28, p = .004). The results were free of heterogeneity and pleiotropy. There were no outliers and the leave-one-out analysis proved that the results were reliable.

CONCLUSIONS

This study provides genetic evidence that pvRSA/HF is causally related to cardiac arrest.

The Sympathetic Nervous System in Hypertensive Heart Failure with Preserved LVEF

The neurohormonal model of heart failure (HF) pathogenesis states that a reduction in cardiac output caused by cardiac injury results in sympathetic nervous system (SNS) activation, that is adaptive in the short-term and maladaptive in the long-term. This model has proved extremely valid and has been applied in HF with a reduced left ventricular (LV) ejection fraction (LVEF). In contrast, it has been undermined in HF with preserved LVEF (HFpEF), which is due to hypertension (HTN) in the vast majority of the cases. Erroneously, HTN, which is the leading cause of cardiovascular disease and premature death worldwide and is present in more than 90% of HF patients, is tightly linked with SNS overactivity. In this paper we provide a contemporary overview of the contribution of SNS overactivity to the development and progression of hypertensive HF (HHF) as well as the clinical implications resulting from therapeutic interventions modifying SNS activity. Throughout the manuscript the terms HHF with preserved LVEF and HfpEF will be used interchangeably, considering that the findings in most HFpEF studies are driven by HTN.

Trends in Passive IoT Biomarker Monitoring and Machine Learning for Cardiovascular Disease Management in the U.S. Elderly Population

It is predicted that the growth in the U.S. elderly population alongside continued growth in chronic disease prevalence will further strain an already overburdened healthcare system and could compromise the delivery of equitable care. Current trends in technology are demonstrating successful application of artificial intelligence (AI) and machine learning (ML) to biomarkers of cardiovascular disease (CVD) using longitudinal data collected passively from internet-of-things (IoT) platforms deployed among the elderly population. These systems are growing in sophistication and deployed across evermore use-cases, presenting new opportunities and challenges for innovators and caregivers alike. IoT sensor development that incorporates greater levels of passivity will increase the likelihood of continued growth in device adoption among the geriatric population for longitudinal health data collection which will benefit a variety of CVD applications. This growth in IoT sensor development and longitudinal data acquisition is paralleled by the growth in ML approaches that continue to provide promising avenues for better geriatric care through higher personalization, more real-time feedback, and prognostic insights that may help prevent downstream complications and relieve strain on the healthcare system overall. However, findings that identify differences in longitudinal biomarker interpretations between elderly populations and relatively younger populations highlights the necessity that ML approaches that use data from newly developed passive IoT systems should collect more data on this target population and more clinical trials will help elucidate the extent of benefits and risks from these data driven approaches to remote care.

Comment on: "exercise training and cardiac autonomic function following coronary artery bypass grafting: a systematic review and meta-analysis"

BACKGROUND

Low cardiorespiratory fitness is associated with poor prognosis in individuals with coronary artery disease and after coronary artery bypass grafting surgery. Thus, we comment about a meta-analysis that adds important information about the effect of exercise training on cardiac autonomic function in individuals following coronary artery bypass grafting surgery.

MAIN BODY

The study by Kushwaha et al. showed positive effects for heart rate variability and heart rate recovery in subjects after coronary artery bypass grafting surgery in response to acute physical training. These data are relevant, since heart rate variability is an independent predictor of for all-cause and cardiovascular mortality for individuals with cardiovascular disorders. Additionally, attenuated heart rate recovery is associated with increased risk for the same outcomes. Moreover, we summarize the quantitative data from studies that compared the effect of physical training in comparison with control group in cardiorespiratory fitness in adults following coronary artery bypass grafting.

CONCLUSIONS

Our findings suggest that improvements in peak oxygen consumption result in an additional benefit in adults following coronary artery bypass grafting. Considered that, the increased cardiorespiratory fitness is an independent predictor of longer survival in coronary artery disease.