Assessment Of Heart Rate Variability Research Articles

Effect of the cholinergic system of the lateral periaqueductal gray (lPAG) on blood pressure and heart rate in normal and hydralazine hypotensive rats.

Due to the presence of the cholinergic system in the lateral periaqueductal gray (lPAG) column, the cardiovascular effects of acetylcholine (ACH) and its receptors in normotensive and hydralazine (HYD) hypotensive rats in this area were evaluated. After anesthesia, the femoral artery was cannulated and systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), and also electrocardiogram for evaluation of low frequency (LF) and high frequency (HF) bands, important components of heart rate variability (HRV), were recorded. ACH, atropine (Atr, a muscarinic antagonist), and hexamethonium (Hex, an antagonist nicotinic) alone and together microinjected into lPAG, changes (Δ) of cardiovascular responses and normalized (n) LF, HF, and LF/HF ratio were analyzed. In normotensive rats, ACH decreased SBP and MAP, and enhanced HR while Atr and Hex did had no effects. In co-injection of Atr and Hex with ACH, only ACH+Atr significantly attenuated parameters. In HYD hypotension, ACH had no affect but Atr and Hex significantly improved the hypotensive effect. Co-injection of Atr and Hex with ACH decreased the hypotensive effect but the effect of Atr+ACH was higher. In normotensive rats, ACH decreased nLF, nHF, and nLF/nHF ratio. These parameters in the Atr +ACH group were significantly higher than in ACH group. In HYD hypotension nLF and nLF/nHF ratio increased which was attenuated by ACH. Also, Atr+ACH decreased nLF and nLF/nHF ratio and increased nHF. The cholinergic system of lPAG mainly via muscarinic receptors has an inhibitory effect on the cardiovascular system. Based on HRV assessment, peripheral cardiovascular effects are mostly mediated by the parasympathetic system.

Decreased Cardiac Autonomic Function is Associated with Higher Exacerbation Risk and Symptom Burden in Chronic Obstructive Pulmonary Disease.

Current measures of chronic obstructive pulmonary disease (COPD) severity, including lung function, do not fully explain symptom burden, and there is a need to identify predictors of exacerbation risk and morbidity. Autonomic dysfunction may be implicated in both cardiovascular and respiratory morbidity in COPD and convey risk for exacerbations. Heart rate variability (HRV) is a marker of cardiac autonomic function that is predictive of cardiovascular health and has promise as a non-invasive COPD biomarker. The CLEAN AIR Heart study provided an opportunity to investigate the association between HRV and COPD morbidity among former smokers with moderate-severe COPD. Eighty-five participants, contributing 305 HRV measurements, underwent repeated clinical assessments over 4 study periods that included a 24-Holter monitoring assessment of HRV. HRV measures of interest were standard deviation of normal-to-normal intervals, (SDNN) (overall HRV) and root-mean-square of successive differences (RMSSD) (parasympathetic function). Exacerbation risk was assessed using negative binomial models, and mixed-effects models analyzed associations between HRV and symptoms. Decreases in SDNN (incidence rate ratio [IRR]1.40; 95% confidence interval [CI] 1.13 to1.74) and RMSSD (IRR 1.60; 95% CI 1.07 to 2.37) were associated with severe exacerbation risk. Decreases in SDNN were associated with higher St George's Respiratory Questionnaire scores, COPD Assessment Test scores, and chronic bronchitis symptoms. Findings demonstrate that HRV is associated with COPD symptom burden and exacerbation risk. HRV may represent an important biomarker with the potential to identify high-risk COPD populations.

Could Heart Rate Variability Serve as a Prognostic Factor in Patients with Pulmonary Hypertension? A Single-center Pilot Study.

Heart rate variability (HRV), which is defined as cyclic changes in sinus rate with time, is used as a measure of cardiac autonomic tone. Our aim was to determine the impact of HRV on short-term prognosis in pulmonary hypertension (PH). We enrolled 64 PH patients and 69 healthy subjects (control group). Patients were evaluated by Holter-ECG, echocardiography, and laboratory tests. 24-h Holter-ECG monitoring was used for HRV. The development of adverse events (right heart failure, hospitalization, syncope, and death) during the 6-month follow-up was evaluated in PH group. PH group (39 ± 16 years, 37.5% males) comprised of 16 patients with idiopathic pulmonary arterial hypertension (PAH) (25%), 36 patients with PAH associated with congenital heart disease (56.3%), 3 PAH associated with connective tissue disease (4.7%), 1 with portopulmonary (1.6%), and 8 chronic thromboembolic PH (12.5%). The time-dependent (standard deviation of all NN intervals for a selected time period [SDNN], standard deviation of the 5-min mean R-R intervals tabulated over an entire day [SDANN], SDNN Index, and Triangular Index) and frequency-dependent HRV indices (low frequency, high-frequency power, and total power,) were significantly reduced in those with PH. Functional class was negatively associated with SDNN, SDANN, SDNN Index, and Triangular Index. Adverse events developed in 25% of the patients during the 6-month follow-up period (200 ± 92 days) (7 patients had right-heart failure, 5 syncope, 12 patients were hospitalized, and 9 had died). All the time and frequency-dependent indices significantly associated with adverse events. Mortality correlated with SDNN (rS = -0.354, P = 0.005), SDANN (rS = -0.368, P = 0.004), SDNN Index (rS = -0.257, P = 0.045), Triangular Index (rS = -0.310, P = 0.014), and VLF (rS = -0.265, P = 0.039). HRV is significantly depressed in patients with PH and is associated with the clinical status. HRV indices might predict clinical deterioration, adverse events, and mortality for 6 months. Non-invasive assessment of HRV through Holter-ECG may be a valuable and practical tool in risk stratification of patients with PH for short-term outcomes.

Influence functional state on special preparedness in rock climbing

The article deals with the problem of disproportionality in a higher heart rate value when climbing relative to running loads at a lower level of oxygen consumption. The aim of the study is to determine influence of functional state on the special climbing preparedness. Study involved children aged 8-12 years in recreation stage of preparation, both sexes in the number of 24 people. To assess the voltage of regulatory systems was used a method for assessing heart rate variability. The study used a method for calculating special preparedness, which allows taking into account the number of the most difficult bouldering routes passed by an athlete during training and their number. The final score depends more on the complexity of the route. It was found that there are no pronounced stresses of the regulatory systems of the body on simple trails (below 6A according to the international classification). With the growth of specific physical loads in rock climbing (the level of trails 6A-6B), athletes face physical efforts requiring the development of coordination and physical capabilities incomparable with the previous level (trails 5A-5S). Also, this level implies more psychological stress. In further complication of specific loads in rock climbing (6C level of trails) is observed the adaptation to the psychophysical efforts. It is concluded that with the growth of functional reserve the heart rhythm increases the adaptation of hands muscles to greater oxygen absorption. Increases tissue capillarization, number of mitochondria and myoglobin in muscle fibers performing specific work in climbing.

Cardiac dysrhythmia in drug-resistant epileptic children

Background Drug-resistant epilepsy is one of the most common neurological conditions associated with high mortality and morbidity rates. Aim To assess heart rate variability among drug-resistant epileptic children. Patients and methods This observational cross-sectional case–control study included 60 epileptic children. Cases were assigned into two equal groups: group 1 (drug-resistant group) included children presented with drug-resistant epilepsy and group 2 (control group) included cases with controlled primary epilepsy who achieved sustained seizure freedom for at least 6 months on one antiepileptic drug, matched with the patient group regarding age and sex. All patients were subjected to history taking and clinical and radiological investigations including computed tomography (CT) and/or MRI and electroencephalogram (EEG) monitoring. ECG monitoring was using Holter ECG. Results MRI, EEG, and ECG abnormalities are significantly more common in drug-resistant epilepsy. Interictal tachycardia was the most prevalent abnormality among group I (93.3%). ECG structure was abnormal in 33.3% in group I, in the form of prolonged QTc interval, ST segment abnormalities, P wave dispersion, and T wave alternans. Tachycardia associated with prolonged QTc interval was present in patients with focal or temporal EEG abnormalities, and patients with multifocal EEG abnormalities. Conclusion ECG monitoring is important in drug-resistant epileptic children to detect any autonomic changes occurring in the heart either ictally or interictally. Heart rate is significantly higher and RR interval is significantly shorter ictally than interictally. Careful monitoring of these changes may help in predicting the risk of sudden unexpected death.

Non-Invasive Assessment of Ultra-Short Time Heart Rate Variability During Wingate Test

The aim of present study was to investigate the sedentary healthy men’s ultra-short heart rate variability (HRV) during the Wingate Anaerobic Test (WAnT) (30-sec) and parasympathetic reactivation in the first 60-sec after WAnT. The final sample comprised 101 individuals (Mean±SD; Age=28.9±4.8 years, Height=176.5±5.5 cm, Weight=89.8±8.8 kg). Anaerobic powers were measured by WAnT. Heart rate variability (HRV) was then recorded as 60-sec before the test for 30-sec and 60-sec after the test. HRV was measured by Polar V800 GPS Sports Watch with Heart Rate Monitor and Polar H7 band. To compare the testing stages HRV parameters, repeated one-way analysis of variance (ANOVA) was used. Binary comparisons were determined with the Bonferroni test. The relationship between exercise data of heart rate variability and power average watt was assessed by the Pearson correlation test. The Effect Size Cohen's d was calculated. The main finding of this study is that pre-test (60-sec) HRV values continue to drop dramatically during test (30-sec) and post-test (60-sec) measurements (p<0.05). Also, no correlation was observed between performance and HRV data during testing (r=-0.08, p>0.05). In conclusion, the present study was not observed to sign of HRV recovery during 60-sec after the 30-sec WAnT. HRV recorded in the first 60 seconds after maximum anaerobic exercise program in sedentary healthy men may be considered to exhibit an imbalance in the parasympathetic activity of the autonomic nervous system.

AGING COUPLES’ SATISFYING RELATIONSHIPS AND WE-TALK PROMOTE CARDIOVASCULAR HEALTH DURING CONFLICT

Abstract Marital conflict poses health risks that intensify as couples grow older. Dyadic stress theories suggest spouses’ marital satisfaction and communication patterns alter cardiovascular function, a key pathway from troubled relationships to poor health. Despite these risks, older spouses are more likely to have a strong couple identity where they think and talk in relational terms. This communication pattern, termed we-talk, is shown when spouses use words like “we” rather than “you” or “me,” reflecting that they are thinking about resolving conflict as a couple rather than as two separate individuals. We examined how both spouses’ relationship satisfaction and we-talk reduced conflict’s cardiovascular toll, and if the health benefits were greatest when both spouses were satisfied and used we-talk. Married couples (n=107) ages 40-87 engaged in a 20-minute conflict discussion while wearing heart rate monitors to assess heart rate variability (HRV), a measure of cardiac flexibility. Couples’ conflicts were transcribed to measure we-talk, or the proportion of first-person plural pronouns, such as we, us, and our. Results showed a person’s HRV was higher and thus healthier when both spouses were satisfied and their partner used we-talk more often. In contrast, HRV was lower and less healthy when neither or only one spouse was satisfied and their partner used we-talk less often. Thus, a couple’s mutually satisfying relationship along with a partner’s we-talk provided a health advantage during conflict. Talking in relational terms may help reduce conflict’s biological toll in aging couples, particularly when their relationships are satisfying.

"We've Got This": Middle-Aged and Older Couples' Satisfying Relationships and We-Talk Promote Better Physiological, Relational, and Emotional Responses to Conflict.

Conflict poses multiple relational and health risks. Dyadic stress theories suggest satisfaction and communication alter cardiovascular and autonomic function, key pathways from troubled relationships to poor health. However, "we-talk," a positive communication pattern, can strengthen relationships and promote health. We examined how each spouse's satisfaction and we-talk were related to conflict's physiological, relational, and emotional toll. Married couples ( n = 107 couples, 214 individuals, ages 40-87 years) who were mostly White, highly educated, and higher-income Americans in different-gender relationships engaged in 20-minute conflict discussions while wearing monitors to assess heart rate variability (HRV). Spouses rated their closeness immediately after conflict and their conflict rumination 2 hours later. Conflict transcriptions measured we-talk, or the proportion of first-person plural pronouns (we, us, our). Satisfied spouses or those in mutually satisfying relationships had higher HRV during conflict ( b = 0.0001, p = .049), felt closer immediately after conflict ( b = 0.07, p < .001), and ruminated less about the conflict 2 hours later ( b = -0.26, p = .026). Spouses' HRV was highest ( b = 0.0002, p = .002) and rumination was lowest ( b = -0.49, p = .019) when they or their partners were satisfied and used we-talk more often. Women's HRV ( b = 0.0001, p = .035) and rumination ( b = -0.01, p = .02) benefited when both spouses were satisfied, as did closeness when women were satisfied ( b = 0.10, p < .001). Men's closeness benefited when they ( b = 0.04, p = .003) or their wives ( b = 0.04, p = .002) were satisfied. The combination of mutually satisfying relationships and we-talk was associated with better relational and health outcomes after conflict. These findings are important for middle-aged and older couples whose relationships are central to their health.

Early Vascular Aging in Obese Individuals with Low Cardiovascular Health

The American Heart Association updated the original recommendations for cardiovascular health (CVH) promotion, defining the Life's Essential 8 (L8). the aim of this cross-sectional study was to compare vascular function, central hemodynamics and autonomic modulation in obese individuals with low and moderate CVH-L8. Both sexes, aged 40-70 years and Body Mass Index ≥30 and <40kg/m2, were submitted to anthropometric and biochemical evaluation, assessment of heart rate variability, endothelial function by flow-mediated dilatation (FMD) and central parameters by oscillometry. The CVH-L8 score was determined using the eight metrics defined in the new classification. Patients (n = 82) were divided according to CVH-L8 classification: moderate group (score CVH-L8 ≥ 50 ≤ 79 points, n = 47) and low group (score CVH-L8 ≤ 49 points, n = 35). Peripheral (119 ± 10 vs 125 ± 15 mmHg, p = 0.048) and central (111 ± 10 vs 118 ± 15 mmHg; p = 0.016) systolic blood pressures and pulse wave velocity (PWV) adequacy (- 0.08 ± 0.34 vs 0.15 ± 0.42m/s, p = 0.008) were significantly higher in low CVH-L8 group. Brachial FMD (9.24 ± 5.41 vs 6.79 ± 4.74%, p = 0.043) were lower in this same group. Only in the low CVH-L8 group low frequency/high frequency (LF/HF) ratio was significantly correlated with PWV (r = 0.338, p = 0.047) and atherogenic index of plasma with Framingham risk score (r = 0.446, p = 0.008), even after adjustment for age and sex. In this sample of obese individuals, low CVH-L8 was associated with higher peripheral and central blood pressures, and evidence of early vascular aging with arterial stiffness and endothelial dysfunction.

The role of autonomic denervation in the success of atrial fibrillation ablation: Can pulsed-field ablation provide the answer?

Although the role of cardiac autonomic nervous system (CANS) in triggering and maintenance of atrial fibrillation (AF) is established, the potential value of adjuvant autonomic denervation in AF ablation is debated. Autonomic denervation from collateral thermal injury of CANS during radiofrequency/cryo-based pulmonary vein (PV) isolation (PVI) is thought to confer additional clinical benefit.1 In contrast, follow-up studies with 24-hour Holter-based heart rate variability (HRV) assessment demonstrated recovery of HRV parameters to the preprocedure level within 3–6 months.

Reduced heart rate variability and expressive suppression interact to prospectively predict COVID-19 pandemic-related post-traumatic stress symptoms.

The COVID-19 pandemic is a unique period of stress that, in some cases, led to post-traumatic stress symptoms (PTSSs). Emotion regulation strategies are known to modulate the emotional response to stressful events. Expressive suppression (ES) is a maladaptive strategy related to the exacerbation of the physiological stress response. Heart rate variability (HRV), an index of cardiac autonomic balance strictly related to ES, was also shown to predict PTSSs. This was the first study to investigate whether the pre-pandemic ES use and resting-state HRV predicted pandemic-related PTSSs. Before the pandemic, 83 (58 females) university students completed the Emotion Regulation Questionnaire (ERQ), self-report measures of anxiety and depressive symptoms, and a three-minute resting-state electrocardiogram recording. After 12months, 61 (45 females) participants completed a self-report measure of pandemic-related PTSSs and repeated the self-report psychological measures. Pre-pandemic anxiety symptoms prospectively predicted greater PTSSs. Moreover, a significant interaction between HRV and ES in predicting PTSSs emerged, whereby those who had higher levels of ES and reduced HRV showed higher PTSSs. These findings suggest that an integrated assessment of HRV and ES might be useful for identifying individuals who are more vulnerable to the development of PTSSs during crises.

Validity and reliability of short-term heart-rate variability from disposable electrocardiography leads.

Single-use electrocardiography (ECG) leads have been developed to reduce healthcare-associated infection. This study compared the validity and reliability of short-term heart rate variability (HRV) obtained from single-use disposable ECG leads. Thirty healthy subjects (33 ± 10 years; 9 females) underwent 5-minresting HRV assessments using disposable (single use) ECG cable and wire system (Kendall DL™ Cardinal Health) and a standard, reusable ECG leads (CardioExpress, Spacelabs Healthcare). Intraclass correlation coefficient (ICC) with 95% confidence interval (CI) between disposable and reusable ECG leads was for the time domain [R-R interval (ms); 0.99 (0.91, 1.00)], the root mean square of successive normal R-R interval differences (RMSSD) (ms); 0.91 (0.76, 0.96), the SD of normal-to-normal R-R intervals (SDNN) (ms); 0.91 (0.68, 0.97) and frequency domain [low-frequency (LF)normalized units (nu); 0.90 (0.79, 0.95), high frequency (HF) nu; 0.91 (0.80, 0.96), LF power (ms2); 0.89 (0.62, 0.96), HF power (ms2); 0.90 (0.72, 0.96)] variables. The mean difference and upper and lower limits of agreement between disposable and reusable leads for time- and frequency-domain variables were acceptable. Analysis of repeated measures using disposable leads demonstrated excellent reproducibility (ICC 95% CI) for R-R interval (ms); 0.93 (0.85, 0.97), RMSSD (ms); 0.93 (0.85, 0.97), SDNN (ms); 0.88 (0.75, 0.95), LF power (ms2); 0.87 (0.72, 0.94), and HF power (ms2); 0.88 (0.73, 0.94) with coefficient of variation ranging from 2.2% to 5% (p > 0.37 for all variables). Single-use Kendall DL™ ECG leads demonstrate a valid and reproducible tool for the assessment of HRV.

Measuring heart rate variability using a heart rate monitor in horses (Equus caballus) during groundwork.

Measuring physiological parameters of stress in horses during groundwork, for example when involved in equine-assisted interventions, is important to gain insight into the stress levels of the horses. Heart rate and heart rate variability can be used as physiological indicators of stress in horses. Heart rate monitors could be easily incorporated into practice, as they are not expensive and easy to use. However, it is questionable whether heart rate monitors present accurate heart rate variability results in exercising horses, similar to electrocardiograms. The aim of this study was to determine the accuracy of heart rate monitors for the assessment of heart rate variability in horses during groundwork exercise. Simultaneous telemetric electrocardiograms (Televet) and heart rate monitor (Polar H10 transmitter and M430 receiver, Hylofit electrodes) recordings were performed on 28 horses (15 mares and 13 geldings). Results indicate that the heart rate monitor accurately determined heart rate and time-domain heart rate variability parameters when compared to electrocardiograms during both baseline and groundwork conditions. As expected, heart rate significantly increased and the heart rate variability significantly decreased during groundwork compared to baseline conditions. This indicates that the heart rate monitor can be used to accurately determine heart rate variability during groundwork.

The Utilization of Heart Rate Variability for Autonomic Nervous System Assessment in Healthy Pregnant Women: Systematic Review

Background The autonomic nervous system (ANS) plays a central role in pregnancy-induced adaptations, and failure in the required adaptations is associated with adverse neonatal and maternal outcomes. Mapping maternal ANS function in healthy pregnancy may help to understand ANS function. Objective This study aimed to systematically review studies on the use of heart rate variability (HRV) monitoring to measure ANS function during pregnancy and determine whether specific HRV patterns representing normal ANS function have been identified during pregnancy. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used to guide the systematic review. The CINAHL, PubMed, SCOPUS, and Web of Science databases were searched to comprehensively identify articles without a time span limitation. Studies were included if they assessed HRV in healthy pregnant individuals at least once during pregnancy or labor, with or without a comparison group (eg, complicated pregnancy). Quality assessment of the included literature was performed using the National Heart, Lung, and Blood Institute (NHLBI) tool. A narrative synthesis approach was used for data extraction and analysis, as the articles were heterogenous in scope, approaches, methods, and variables assessed, which precluded traditional meta-analysis approaches being used. Results After full screening, 8 studies met the inclusion criteria. In 88% (7/8) of the studies, HRV was measured using electrocardiogram and operationalized in 3 different ways: linear frequency domain (FD), linear time domain (TD), and nonlinear methods. FD was measured in all (8/8), TD in 75% (6/8), and nonlinear methods in 25% (2/8) of the studies. The assessment duration varied from 5 minutes to 24 hours. TD indexes and most of the FD indexes decreased from the first to the third trimesters in the majority (5/7, 71%) of the studies. Of the FD indexes, low frequency (LF [nu]) and the LF/high frequency (HF) ratio showed an ascending trend from early to late pregnancy, indicating an increase in sympathetic activity toward the end of the pregnancy. Conclusions We identified 3 HRV operationalization methods along with potentially indicative HRV patterns. However, we found no justification for the selection of measurement tools, measurement time frames, and operationalization methods, which threaten the generalizability and reliability of pattern findings. More research is needed to determine the criteria and methods for determining HRV patterns corresponding to ANS functioning in healthy pregnant persons.

Bedside tracking of functional autonomic age in preterm infants.

Preterm birth predisposes infants to adverse outcomes that, without early intervention, impacts their long-term health. To assist bedside monitoring, we developed a tool to track the autonomic maturation of the preterm by assessing heart rate variability (HRV) changes during intensive care. Electrocardiogram (ECG) recordings were longitudinally recorded in 67 infants (26-38 weeks postmenstrual age (PMA)). Supervised machine learning was used to generate a functional autonomic age (FAA), by combining 50 computed HRV features from successive 5-minute ECG epochs (median of 23 epochs per infant). Performance of the FAA was assessed by correlation to PMA, clinical outcomes and the infant's functional brain age (FBA), an index of maturation derived from the electroencephalogram. The FAA was strongly correlated to PMA (r = 0.86, 95% CI: 0.83-0.93) with a mean absolute error (MAE) of 1.66 weeks and also accurately estimated FBA (MAE = 1.58 weeks, n = 54 infants). The relationship between PMA and FAA was not confounded by neurodevelopmental outcome (p = 0.18, n = 45), sex (p = 0.88, n = 56), patent ductus arteriosus (p = 0.08, n = 56), IVH (p = 0.63, n = 56) or body weight at birth (p = 0.95, n = 56). The FAA, an index derived from the ubiquitous ECG signal, offers direct avenues towards estimating autonomic maturation at the bedside during intensive care monitoring. The development of a tool to track functional autonomic age in preterm infants based on heart rate variability features in the electrocardiogram provides a rapid and specialized view of autonomic maturation at the bedside. Functional autonomic age is linked closely to postmenstrual age and central nervous system function response, as determined by its relationship to functional brain age from the electroencephalogram. Tracking functional autonomic age during neonatal intensive care unit monitoring offers a unique insight into cardiovascular health in infants born extremely preterm and their maturational trajectories to term age.

Effect of Physical Training on the Morphology of Parasympathetic Atrial Ganglia after Unilateral Vagotomy in Rats.

Cardiac denervation is a serious problem in a number of patients, including patients after heart transplantation. The status of the parasympathetic ganglia after crossing the preganglionic fibers of the vagus nerve has not been enough studied. The aim of our study was to assess the effect of physical training on the morphological parameters of the parasympathetic atrial ganglia and autonomic regulation of heart rate after right- and left-sided vagotomy in rats. Morphometric characteristics of the right atrial ganglia were evaluated using an immunohistochemical method after a study that included a three-time assessment of heart rate variability. It was found that right-sided vagotomy leads to both an increase in the volume of ganglion and autonomic dysfunction. No significant change in the number of nerve cells was found in animals with false and left-sided vagotomy while maintaining preganglionic innervation after the physical training, whereas exercises led to a decrease in the volume of nerve tissue of rats with right-sided denervation. It was also found that in animals with preserved vagal innervation, the volume of atrial ganglion tissue correlates with overall heart rate variability and a normalized parasympathetic component. Therefore, a positive effect from regular physical activity on parasympathetic regulation can be expected only if preganglionic vagal influence is preserved.

Evaluating the relationship between neurological function, neuromuscular fatigue, and subjective performance measures in professional rugby union players.

Managing the health and wellbeing of full-time professional athletes is a multifaceted task. In elite high-performance environments, medical staff and strength training coaches attempt to identify improved methods to monitor player health. Monitoring player health could indicate potential injury risk and assist in adjustments to training and workload management. Measuring fatigue is a notable component of monitoring player readiness before and after training sessions, and after competitive fixtures. In the present study, a novel method of gathering non-invasive player data was investigated by utilizing the Omegawave (OW) to monitor direct current (DC) potential brainwave activity. This method allowed for non-invasive data gathering to assess recovery, player readiness and indicators of workload that may affect optimal performance. DC potential is based on recording low electrical frequencies (>0.5 Hz) that is derived from (1) Stabilization point of DC potential (mV), (2) Stabilization time (1.0-7.0) and (3) Curve shape (1.0-7.0). These measures evaluate the athlete's internal stress, readiness to perform, and neurological function through DC potential brain wave activity and heart rate variability (HRV) assessments. The primary aim of this case series was to compare the efficacy of objective DC potential brainwave activity measurements (neurological function) with neuromuscular fatigue data using reactive strength index modified (RSImod) and profile of mood states (POMS) questionnaires to assess a player's state of readiness to train. The participants in this study were eleven male senior professional rugby union players with a mean stature (±SD) of 185.2 ± 8.6 cm, mass of 101.1 ± 12.9 kg, and age of 27.1 ± 2.1 years. All players were tested 3 days per week over a 6-week mid-season period. Results from this case study suggest that DC potentials could be used as an objective measure to indicate player readiness and managing individual player workload. The final analyses identified a weak negative correlation (r = -0.17) between the RSImod data and the DC potential data was observed. DC potential brainwave activity data could be used in conjunction with subjective measures such as POMS, RSImod and reported injury status to adjust player daily activity.

Monitoring Heart Rate Variability and Its Association with High-Intensity Running, Psychometric Status, and Training Load in Elite Female Soccer Players during Match Weeks

In order to maximize adaptations to reach high performance, sports coaches must regularly monitor the healing process following competitions or important training sessions and maintain psychometric status. As a result, the objective of this study was to track heart rate variability (HRV) in elite Spanish female soccer players during match weeks and examine its connection to high-intensity running, psychometric status, and training load. Changes in the nocturnal HRV measured along the square root of differences between adjacent RR intervals of 4 h (rMSSD 4 h) during the first phase of slow wave sleep (rMSSD 5 min), resting heart rate (RHR 4 h and RHR 5 min) were recorded with Firstbeat Bodyguard 2 (Firstbeat Technologies, Jyvaskyla, Finland). Training and match loads were recorded with rating perceived exertion and high-intensity running data by using a global positioning system (GPS) device (SPI-Pro X, GPSports). Ultimately, the psychometric test was recorded by a 5-item questionnaire, and all data were analyzed across three weeks of a competitive season. The day of the match found the lowest HRV, while the day following the match found a substantial (p &lt; 0.01) rise in rMSSD 4 h and rMSSD 5 min. Similarly, these variables showed significant differences two days after the match. Similarly, these variables showed significant differences two days after the match. Furthermore, significant differences were found between the RHR 4 h and RHR 5 min (p &lt; 0.01) and rMSSD 4 h and rMSSD 5 min (p &lt; 0.05) and variables after two days with a higher training load. The results gathered from the psychometric tests, and the various HR markers showed significant associations. As a result, HRV, RHR, and psychometric assessments are probably sensitive to changes in load within a microcycle, providing a straightforward and non-invasive technique to assess changes in the recovery/fatigue status of top-level female soccer players.

Оценка функциональных резервов организма первокурсников северного педагогического вуза по результатам ортостатической пробы

The success of adaptation to the standard minimum load (using orthostatic test as an example) is primarily determined by the ability of the regulatory systems to restructure the activity of the cardiovascular system without involving the central regulatory circuit. Evaluation of the body’s functional reserves can provide the basis for characterization of its adaptive capabilities as a whole. The aim of this study was to assess the body’s functional reserves in first-year students of a pedagogical university in northern Russia according to the results of an orthostatic test. Materials and methods. A total of 135 first-year students of Surgut State Pedagogical University were examined, their mean age being 18.3 ± 0.33 years. Cardiointervalography (VNS-spektr device, Neurosoft, Russia) was used to assess heart rate variability at rest and during an active orthostatic test. Results. Total power, as well as absolute low frequency and very low frequency power decreased during the orthostatic test in both groups. It was found that 23 % of male and 16 % of female students had a reduced reaction to the orthostatic test. High level of adaptation reserves was observed in 30 % of first-year students. At the same time, we identified groups with a low level of adaptation reserves (8.8 % of male and 2 % of female students). The research established that the level of the body’s functional reserves in young women was higher than that in young men. In addition, female students showed a bigger contribution of the central circuit to heart rate regulation. Young men demonstrated high parasympathetic reactivity and a greater contribution of subcortical centres to heart rate regulation, compared to young women.

Heart rate variability is associated with cerebral small vessel disease in patients with diabetes.

Low heart rate variability (HRV), an indicator of autonomic nervous system dysfunction, has been associated with increased all-cause and cardiovascular mortality and incident stroke. However, the relationship between HRV and cerebral small vessel disease (CSVD) showed contradictory results. We aimed to examine the relationship of HRV and total burden of CSVD and each of the magnetic resonance imaging (MRI) markers of CSVD. We recruited 435 patients who attended our hospital for physical examination between June 2020 and August 2021. All underwent 24-h Holter monitoring and MRI scan. The standard deviation of normal-to-normal intervals (SDNN) was selected as the method for HRV assessment. The presence of severe white matter hyperintensity, lacunes, and >10 enlarged basal ganglia perivascular spaces, and cerebral microbleeds were added for estimating the CSVD score (0-4). Multivariate logistic analyses was performed to assess whether HRV was independently associated with the burden of CSVD and each of the MRI markers of CSVD, with and without stratification by prevalent diabetes. This study included 435 subjects with a mean age of 64.0 (57.0-70.0) years; 49.4% of the patients were male, and 122 (28.0%) had a history of diabetes. In multivariate analyses, lower SDNN was independently associated with total burden of CSVD and the presence of enlarged perivascular spaces in all subjects. According to diabetes stratification, lower SDNN was independently associated with total burden of CSVD and each MRI markers of CSVD separately only in the diabetic group. Lower HRV was associated with total burden of CSVD and each MRI markers of CSVD separately among diabetic patients, but not among non-diabetic patients.