Introduction: heart-rate variability (HRV), respiratory-rate variability (RRV) and the pulse-respiration quotient (PRQ) reflect autonomic modulation, yet their relationship with university dietary habits remains understudied. Objective: to examine the association between dietary patterns and autonomic activity among university students. Methods: ninety-one young adults were classified, via factor analysis, into a healthy (PDS) or an unhealthy (PDNS) dietary pattern. From 5-min beat-to-beat (RR) and breath-to-breath (BB) recordings we extracted: high-frequency log power (HFlog), parasympathetic (PNS) and sympathetic (SNS) indices, stress index, mean RR interval (Mean RR), fractal exponents α₁ and α₂, Poincaré dispersion (SD₂), and the low- to high-frequency power ratio (LF/HF). For RRV we obtained mean breathing rate (BRmean) and BB deviation (SDBB); for PRQ we calculated mean PRQ (mPRQ). Student's t-, Mann-Whitney U-tests and Spearman correlations were applied (p ≤ 0.05). Results: fifty-three percent of participants followed the PDNS. In men, the PDS showed higher HFlog and α₁ ≈ 1. Within the PDS, lean animal products were linked to ↓SNS, ↓stress, ↓α₂ and ↑Mean RR; non-fat cereals to ↑PNS and ↓LF/HF in men; fruits-vegetables to ↓BRmean and ↑SDBB; legumes and canned fish to ↓mPRQ. In the PDNS, sugary drinks decreased PNS, HFlog and SD₂ but increased SNS in women, and raised stress and α₂ in men; fat-rich cereals elevated α₂. Conclusion: the PDS enhances vagal tone, fractal stability and cardiorespiratory synchrony, whereas the PDNS heightens sympathetic activity and lowers variability, particularly in women. These findings support early nutritional interventions that foster the PDS.

Early social skills underlie the development of crucial regulatory and behavioral processes across childhood. EEG frontal alpha asymmetry and heart rate variability are two physiological markers that have been extensively studied in relation to social skills in high-income country (HIC) samples. The prevalence of adversities in low- and middle-income countries (LMICs) is linked to pervasive deficits in early social skills, yet little is known about the role of physiology in contributing to these processes. The current study explores two physiological measures across two timepoints in relation to social skills in a rural, low-resourced context. In a sample of 229 young children from Greater Tzaneen, South Africa, we assessed how both frontal alpha asymmetry and change in heart rate variability from 17 to 36 months related to 36-month social skills. Left frontal asymmetry predicted poorer social skills, while greater increase in heart rate variability across timepoints predicted higher social skills, especially in children displaying right-lateralized asymmetry. Findings extend work from HICs to a LMIC context, suggesting potential implications for later mental health challenges, while identifying autonomic maturation as a possible protective factor in low-resource settings for specific neurophysiological profiles.

Ultrafine particles exposure and early subclinical cardiovascular effects from shipping and port activities.

Introduction: Wound healing following abdominal surgeries such as elective Lower Segment Caesarean Section (LSCS) is a multifactorial process influenced by physiological and psychological factors. Elevated psychological stress adversely affects immune system performance, which can lead to slower tissue regeneration and heightened susceptibility to postoperative complications. Meditation grounded in yoga principles, characterised by controlled breathing and mindful awareness, has been documented to lower stress and inflammation while supporting autonomic nervous system stability. Despite these potential benefits, there is limited clinical evidence evaluating the direct role of yoga-based meditation in improving surgical wound healing. Aim: To evaluate the impact of yoga-based meditation on stress levels and wound healing outcomes in patients after elective LSCS. Materials and Methods: A randomised controlled trial was conducted in July 2022 at the Department of Obstetrics and Gynaecology, Shri B.M Patil Medical College, Hospital and Research Centre, Vijayapura, Karnataka, India. The study included 52 patients undergoing elective LSCS, who were randomly assigned to two groups: an intervention group and a control group. Participants were recruited at the time of admission to the postnatal ward. The intervention group received guided yoga-based meditation for 15 minutes, three times daily, over a period of 14 consecutive days. Meditation sessions focused on breath awareness, relaxation techniques, and mindfulness. The control group received standard postoperative care without meditation. Stress parameters and wound healing outcomes were assessed at baseline and on day 14. The parameters measured included Heart Rate (HR), Heart Rate Variability (HRV), Perceived Stress Score (PSS), and Galvanic Skin Response (GSR). Wound healing was assessed using the Southampton wound grading system. Statistical analysis was performed using International Business Machine (IBM) Statistical Packages of Social Sciences (SPSS) Statistics version 25.0. Between-group comparisons were made using the chi-square test for categorical variables and the Mann-Whitney U test for non parametric continuous variables. A p-value of <0.05 was considered statistically significant. Results: Of the 70 patients enrolled, 52 completed the trial (26 per group). There were no significant baseline differences in age, Body Mass Index (BMI) or parity (p>0.05). After 14 days, the yoga-meditation group showed a greater reduction in resting HR (mean change -14.48% vs -4.02%; p<0.001), a greater increase in HRV (mean change +21.81% vs +8.75%; p<0.001), and a greater reduction in PSS score (-48.2% vs -47.4%; p=0.013) compared with controls. GSR showed a marked increase, indicating enhanced parasympathetic activity. Although both groups achieved 100% Grade 0 healing by day 14 (Southampton Wound Grading System), the meditation group demonstrated a more rapid resolution of early inflammatory signs in the first week. Conclusion: Adjunctive yoga-based meditation significantly attenuates postoperative stress- both physiological and psychological and may accelerate the initial phases of wound healing following elective LSCS. This non invasive, low-cost intervention holds promise for enhancing recovery and patient well-being in the postoperative setting.

Beyond age and expertise: Emotional intelligence and heart rate variability predict decision-making under risk in mountain-guide population.

Seizure-related biomarkers of sudden unexpected death in epilepsy (SUDEP) in drug-resistant focal epilepsy (REPO2MSE): a prospective, multicentre case-control study.

Psychobiological reactivity to acute psychological stress as a predictor of cardiovascular disease and mortality: The Multi-Ethnic Study of Atherosclerosis.

Wii-training improved cardiac autonomic control of children with developmental coordination disorder: A randomized controlled trial.

Introduction: Academic stress can inhibit and suppress learning, a phenomenon referred to as “unfavorable stress,” which is associated with diminished academic performance. It is a proven fact that medical students experience this stress from the moment they enter the profession, and it continues throughout their lives. Therefore, the association between stress and cardiac autonomic functions has been studied. Exposure to various stressors stimulates multiple stresscontrolling mechanisms in the body. The primary focus of the present study was to measure stress and its effects on the cardiovascular system, as well as its subsequent impact on academic performance. Aim: To measure stress in medical students using Heart Rate Variability (HRV) and Perceived Stress Scale (PSS) scores, and to relate these measurements to their academic achievements. Materials and Methods: The present cross-sectional observational study was conducted on 60 healthy medical students at Faculty of Medicine and Health Sciences (FMHS) SGT Medical College, Gurugram, Haryana, India, after obtaining approval from the Institutional Ethics Committee. The study lasted for two months, from June 2022 to July 2022. All enrolled students who provided consent and were studying during the study period were selected through a random allocation technique. One week before the sessional examinations, PSS scores, 15 minutes of HRV data, and scores from Multiple-Choice Questions (MCQs) were obtained. Statistical analysis was performed using Analysis of Variance (ANOVA), which showed significant results with p<0.005. Out of 150 students, a total of 60 were included in the study. Demographic parameters were not considered, and ANOVA and t-tests were used with a confidence interval of 95%. A p-value less than 0.05 was considered significant. Results: A total of 44 (73.33%) students reported moderate stress one week before the first internal examination, while only 24 (40%) students reported moderate stress one week before the second internal examination. This highlights that coping strategies help individuals tackle stressful situations. Conclusion: Stress can be beneficial to some extent for the academic achievement of students, but not always. Additionally, the present study provides insights into understanding the stress levels of students from the onset, which can assist them in managing schoolwork and academic achievements.

The role of separation anxiety and autonomic dysregulation in pediatric vasovagal syncope. A cross-sectional study.

Disassembling infra-low-frequency neurofeedback: A neurophysiological investigation of its feedback components.

Cardiac autonomic dysfunction plays a crucial role in the pathogenesis of common cardiovascular diseases. The review discusses current and emerging techniques in the evaluation of cardiac autonomic tone. Assessment techniques include invasive nerve recordings, neurochemical staining, serum biomarkers, advanced imaging, and autonomic reflex testing. Noninvasive modalities such as heart rate variability and skin sympathetic nerve activity have improved clinical feasibility. Novel radiotracers and serum-based assays are emerging to map neurotransmitter dynamics and receptor activity with greater precision. No single method captures the full spectrum of autonomic function. A multimodal approach, integrating structural, functional, and molecular tools, offers a more comprehensive evaluation. Future strategies combining imaging, transcriptomics, and biomarkers may enable earlier detection and guide personalized neuromodulation therapies in cardiovascular care.

The hypothesis was that stress in horses getting accustomed to a vibrating plate could be reduced within seven days. Based on this hypothesis, the aim of the study was to analyze the heart rate variability parameters of horses during their acclimation to the vibrating plate. The study involved 10 warmblood horses aged 9-21 years. The study was conducted on a Technohorse vibrating plate (platform). The experiment was planned for seven consecutive days. During the first three days, the horses were accustomed to entering the space containing the vibrating plate and to being placed on the on the device itself. During the next four days, the horses were placed on the vibrating plate, and then a three-minute program was initiated. Heart rate variability (HRV) parameters were also measured during the experiment. Based on the obtained results, it can be concluded that the assumed seven-day period is sufficient to prepare the horses for relaxation treatments on the vibrating plate. The observed ranges of heart rate variability parameters illustrate clear differences between the first and subsequent measurements, indicating lower emotional arousal of the horses on subsequent days of their acclimation to vibrotherapy. Activating the platform itself did not affect the activity of the horses’ autonomic nervous system when comparing the first and last activation of the device during the experiment. The heart rate (bpm) parameter, may be useful in assessing the emotional state, which may have significant application implications in terms of the use of vibrations in the regeneration of the horse’s body.

Autonomic and hormonal biomarkers in individuals with autism spectrum disorders and developmental or intellectual delay: A systematic PRISMA review.

Cardiac sympathetic-parasympathetic activity and reactivity during mentalizing in healthy young adults.

Interoceptive mechanisms of a mobile heart rate variability biofeedback app for eating disorder symptoms: Proof-of-concept findings.

Brain network localization of high-frequency heart rate variability: A meta-analysis and coordinate-based network mapping approach.

Cardiovascular diseases (CVDs) remain a leading cause of mortality worldwide, necessitating the identification and analysis of key risk factors. This study examines the epidemiological effects of cardiovascular risk factors, such as heart rate variability (HRV) and electrocardiogram (ECG) analysis, diabetes, smoking, alcohol use, obesity, and hypertension focusing on cardiovascular diseases (CVD) in India, with a specific emphasis on the state of Madhya Pradesh. It investigates the relationship between heart rate (HR) and various risk factors associated with cardiovascular problems, along with an assessment of heart rate variability (HRV) as an indicator of cardiovascular health. Through a comprehensive analysis of epidemiological data, the study identifies key risk factors contributing to the prevalence of CVD in the region, including lifestyle habits, socio-economic factors, and genetic predispositions. Utilizing both crosssectional and longitudinal data, the research evaluates the impact of these risk factors on HR and HRV. Findings highlight significant correlations between elevated HR, reduced HRV, and increased cardiovascular risk, providing insights into the potential for HRV assessment as a diagnostic tool for early detection and management of CVD. This study aims to contribute to a deeper understanding of cardiovascular health dynamics in Madhya Pradesh and offer evidencebased recommendations for public health interventions.

We know that ischaemic cardiomyopathy leads to compensatory changes in the cardiovascular system to offset the reduction in cardiac output; there is a marked increase in cardiac sympathetic drive, as measured by noradrenaline spillover, and a marked increase in sympathetic vasoconstrictor drive to the skeletal muscle vascular bed, as measured by recording muscle sympathetic nerve activity from a peripheral nerve. Conversely based on assessment of heart rate variability there is believed to be a decrease in cardiac parasympathetic drive. Accordingly we might expect a decrease in ongoing neural activity in the vagus nerve. To test this we performed microelectrode recordings from the right vagus nerve in 14 patients with ischaemic cardiomyopathy and left ventricular ejection fractions ranging from 30%-48%. Multiple intrafascicular sites were analysed in each participant, with 57 multiunit sites being identified in which ongoing neural activity exhibited cardiac rhythmicity. Construction of cross-correlation histograms between the neural activity and the ECG demonstrated that there was no reduction in cardiac-modulated neural activity when compared to a group of healthy controls. Rather the magnitude of cardiac modulation of vagal activity was significantly elevated in ischaemic cardiomyopathy: 30.8%±13.7% (mean±SD) vs. 18.1%±18.0% (P<0.0001). Conversely there was no significant difference in the magnitude of respiratory modulation of vagal activity (48.0±24.6% vs. 40.7%±22.7%, P=0.1122). We conclude that ongoing cardiac-modulated activity in the right vagus nerve is elevated in ischaemic cardiomyopathy. Given that most of the vagus nerve is sensory we interpret this as reflecting an increase in afferent activity from the failing heart. KEY POINTS: Intraneural recordings from the cervical vagus were obtained in awake patients with ischaemic cardiomyopathy via tungsten microelectrodes inserted into the nerve through ultrasound guidance. Cross-correlation analysis of multiunit vagal activity revealed cardiac and respiratory modulation, from which the amplitude of modulation could be computed. We expected cardiac-locked vagal activity to be reduced, given the evidence for an overall reduction in heart rate variability in heart failure and the interpretation that this largely reflects an increase in cardiac sympathetic drive and a decrease in parasympathetic drive. However compared to data obtained in healthy participants the magnitude of cardiac modulation of vagal activity was significantly elevated in ischaemic cardiomyopathy (31% vs. 18%), but there was no significant difference in the magnitude of respiratory modulation of vagal activity (48% vs. 41%). We interpret this as reflecting an increase in afferent activity from the failing heart.

ABSTRACT Cognitive decline of elderly is significant, and early diagnosis is the key to improving long term outcomes. The existing approaches to the cognitive impairment diagnosis are usually costly, time-consuming, and are mainly based on clinical tests, which may overlook the early indicators. In the work, we suggest using smart watches, more precisely heart rate variability (HRV), physical activity and sleep patterns, and machine learning algorithms to predict cognitive decline. Our model Support Vector Machine (SVM) has good accuracy with 98.21% accuracy, 98.21% precision and 98.21% recall. The low rates of errors are together shown by the method having low false positive rates and false negative rates. Such advances demonstrate the success of wearable technology when it comes to monitoring health on a constant basis and non-invasively. This work contributes to the development of an early method of impairment detection, which is easily accessible and used in real-time, and will greatly improve tailored care of the elderly group.