Assessment Of Heart Rate Variability Research Articles

Ecg Features of Cardiac Autonomic Neuropathy In Patients With Type 2 Diabetes Mellitus

IntroductionCardiac autonomic neuropathy (CAD) is associated with a poor cardiac prognosis, particularly with an increased risk of sudden death in diabetic patients. A lengthening of the QT interval and alteration of the QT dispersion have been reported in patients with diabetic CAD as well as increased sympathetic activity confirmed by the heart rate variability (HRV) assessment. Material and MethodsWe conducted a randomized study: 77 patients were enrolled in the Sumy Region Affair Hospital, among them 46 had type 2 diabetes mellitus (DM) for 5 years and longer (group A), 31 had normal glucose profile, history of DM was absent (group B). Our patients have been subjected to physical examination, blood tests (glucose, HbA1c, lipid profile), 12-lead ECG with HRV measure. The authors had full access and take responsibility for the integrity of the data. ResultsIt was detected that in patients with DM QTc interval values were close to the upper limits (461.5±26.61ms). The QTc averages of normal-to-normal (NN) intervals (SDANN), root mean square differences of successive NN intervals (RMSSD) and low-frequency (LF) – high-frequency (HF) power ratio were significantly higher in patients with DM (p<0.05). LF/HF was statistically linked to the increase of HbA1c and decrease of magnesium level. It was detected that changes could be improved by the glucose level control and treatment with magnesium supplements 100 mg per day for 30 days (p<0.05). ConclusionCAD is associated with QT prolongation and HRV disturbances. Further research of possible long-term consequences and approaches to their correction is required.

Neurophysiological features in patients with migraine at risk for epilepsy

Objective: to study the electrophysiological parameters of brain bioelectric activity and features of the autonomous nervous system assessing heart rate variability, sympathetic skin response, clinical and physiological tests depending on the lateralization of migraine pain syndrome in the right or left brain hemisphere in patients with epileptic electroencephalogram (EEG) signs and migraine.Material and methods. Thirty six patients with aura-free episodic migraine at risk of developing epilepsy and 9 age-matched healthy subjects were examined. All participants underwent EEG, clinical and physiological tests, assessment of heart rate variability and sympathetic skin response.Results. Patients with right-hemisphere migraine headache had signs of activated sympathetic nervous system at baseline level and during exercise, lower baseline EEG epileptiform activity and in provocative tests. In contrast to the subjects of this group, patients of other group featured with a more stable migraine pain syndrome in the left hemisphere tended to dominate with functional activity of the parasympathetic system such as increased trophotropic support during exercise, as well as greater magnitude of baseline epileptiform bioelectric activity and during load tests.Conclusion. Values of heart rate variability in combination with objective results of clinical and physiological assessment of the autonomous nervous system and electrophysiological parameters of brain bioelectric activity are reliable prognostic indicators for varying functional conditions in patients with episodic migraine.

Evaluation of heart rate variability in patients with different forms of pulmonary hypertension

Pulmonary hypertension (PH) is a severe pathology of the cardiovascular system with extremely poor prognosis, if unreated. Early diagnosis of PH is difficult, due to the absence pathognomonic symptoms, and at the initial stage the disease may be asymptomatic. An increase in pulmonary vascular resistance and pressure in the pulmonary artery cause severe dysfunction of the right ventricle, which affects the functional status of patients. The assessment of heart rate variability (HRV) parameters is used to predict the increased risk of sudden death in various diseases of the cardiovascular system and the functional status of the body. HRV is mainly regulated by the sympathetic and parasympathetic divisions of the autonomic nervous system. It is noted that pulmonary arterial hypertension is associated with increasing of sympathetic activity. The review, based on the analysis of the pathophysiological mechanisms of pulmonary arterial hypertension and chronic thromboembolic PH, presents the results of studies assessing the time and spectral parameters of HRV in patients with PH of various etiologies.

Effects of interdialytic interval on heart rate variability in chronic hemodialysis patients: a cross-sectional study

Previous studies showed that long interdialytic interval of chronic hemodialysis increased risk of sudden cardiac death compared to short interdialytic interval. Diabetes mellitus (DM) and autonomic dysfunction are the strong adverse predictors of survival in ESRD patients. We aimed to compare autonomic function between long and short interdialytic interval of chronic hemodialysis in patients with and without DM. One-hundred sixty-three patients receiving chronic hemodialysis were enrolled. The electrocardiogram recording was performed twice in each patient during 4-h hemodialysis session after long and short interdialytic intervals to assess heart rate variability (HRV). Mean age was 61.4 ± 14.3 years. HRV parameters during hemodialysis did not differ between long and short interdialytic interval in overall population. Nevertheless, in 82 (50.3%) patients, SDNN (47.4 ± 23.8 vs. 43.4 ± 19.5 ms, P = 0.039), ASDNN (24.8 ± 14.3 vs. 22.7 ± 12.3 ms, P = 0.025), LF (8.4 ± 6.8 vs. 7.6 ± 6.6 ms2, P = 0.040) increased after long interdialytic interval. The greater change of SDNN, ASDNN, VLF and LF between long and short interdialytic intervals was noted in DM, compared to non-DM patients. We demonstrated that there was no difference of HRV parameters after short and long interdialytic interval. However, there was greater autonomic alteration observed in DM than non-DM patients between 2 interdialytic intervals.

Outcomes and Prognosis of Non-Elderly Patients with Brain Metastases-A Prospective Cohort Incorporating Individualized Assessment of Heart Rate Variability.

Outcomes and prognostic factors among patients with brain metastases (BM) have been widely studied, but seldom for the non-elderly. Heart rate variability (HRV) is a physiological phenomenon and has been shown as a survival prognostic factor in cancer patients. This study aimed to evaluate the outcomes and prognosis among non-elderly BM patients with the incorporation of HRV analysis. Forty non-elderly BM patients treated using whole brain radiotherapy (WBRT) were studied from January 2010 prospectively with 5-min electrocardiography (ECG) recordings. Individualized HRV was generated by the ECG, and the time domain HRV index SDNN was chosen for survival analysis. The median overall survival (OS) for the entire group was 6.21 months. Univariate analysis revealed that a KPS < 80 (p = 0.019) and an SDNN < 10 ms (p = 0.007) demonstrated statistical significance for OS; multivariate analysis confirmed that a KPS < 80 (p = 0.004; HR = 3.060, CI = 1.437–6.517) and an SDNN < 10 ms (p = 0.010; HR = 2.664, CI = 1.262–5.624) were independent prognostic factors. Prospective studies for risk stratification among non-elderly BM patients based on our results are warranted to validate our findings.

Reactive Hyperemia-Triggered Wrist Pulse Analysis for Early Monitoring of Young Men with High Atherosclerotic Risk.

The high prevalence of cardiovascular disease in young adults has raised significant concern regarding the early identification of risk factors to allow for timely intervention. This study aimed to identify young males at risk of atherosclerosis using a noninvasive instrument and an initial application percussion entropy analysis of the wrist pressure pulse (WPP). In total, 49 young males aged 18 to 28, without any known history of vascular disease, were recruited. Blood samples were obtained whereby a TC/HDL cutoff value of 4 was used to divide the young men into low-risk (Group 1, TC/HDL < 4, N = 32) and high-risk (Group 2, TC/HDL ≥ 4, N = 17) groups regarding atherosclerosis. The reactive hyperemia-triggered WPPs were measured using a modified air-pressure-sensing system (MAPSS). The dilation index (DI) of the endothelial function and percussion entropy index (PEI) of the heart rate variability (HRV) assessments, calculated using pragmatic signal-processing techniques, were compared between the two groups. The nonparametric Mann–Whitney U test showed that the DI and PEI of the two groups showed statistical differences (both p < 0.05). Not only could the MAPSS assess endothelial function and HRV in young males, but the results also showed that waist circumference and PEI may serve as indicators for the early identification of young males at risk of atherosclerosis.

Assessment of heart rate variability and tone of the autonomic nervous system in puberty-aged children with undifferentiated connective tissue dysplasia

Abstract Within the framework of the research into pathological conditions and syndromes associated with undifferentiated connective tissue dysplasia (UCTD), an emphasis needs to be placed on the changes in heart rhythm. In puberty, the severity of neurovegetative disorders caused by the presence of UCTD might increase manifold. The features of heart rate variability (HRV) in pubertal children against the background of UCTD have been studied insufficiently and require more detailed analysis. This study aims to assess heart rate variability and tone of the autonomic nervous system (ANS) in puberty-aged children with UCTD. Two groups of children were examined, with methods including electrocardiography and cardiointervalography. The main group consisted of 36 puberty-aged children with UCTD, the control group consisted of 30 healthy children. ANS tone was assessed based on the HRV. In the control group of children aged 11, the value of variation range (VR) was 0.18±0.4, mode amplitude (MA) 35.2±2.4, stress index (IN) 72.8±4.3, which corresponds to the state of vegetative balance. As the puberty progresses, the state of eutonia is replaced by the activation of the sympathetic division of the ANS, which becomes most pronounced at the age of 13 years. In the control group of children aged 13, the value of VR was 0.08±0.02, MA 61.7±2.1, SI 210.6±8.6, which corresponds to moderate sympathicotonia. By the end of puberty, in healthy children, the severity of sympathetic activation begins to decrease, and at the age of 15 years, vegetative balance is again observed. However, this pattern is violated in children with UCTD. Upon entering puberty, moderate activation of the sympathetic division of the ANS is already observed in children with UCTD. At the age of 11 years in this group, the value of VR is 0.06±0.02, MA 72.4±3.1, SI 211.2±8.6. At the age of 13, pronounced sympathicotonia is observed, which is confirmed by the values of VR - 0.04±0.01, MA 80.2±4.3 and SI 34.3±14.7. By the end of puberty in children with UCTD, in contrast to the control group, the analyzed parameters indicate not an equilibrium of the ANS, but the predominance of parasympathetic activation. The research provides an insight into heart rate variability in puberty-aged children with UCTD. It was established that healthy children enter puberty in a state of equilibrium of the autonomic nervous system, which in the middle of puberty is replaced by moderate sympathicotonia, and then returns to its original values. Children with the presence of UCTD enter puberty with moderately pronounced sympathicotonia, which gradually increases to pronounced values and is replaced by moderate vagotonia. Funding Acknowledgement Type of funding sources: None.

Compliance Using Mobile Health Heart Rate Variability and Ecological Momentary Assessment Tools in a Chronic Traumatic Brain Injury Sample

<h3>Research Objectives</h3> To assess compliance with repeated heart rate variability (HRV) and ecological momentary assessments (EMA) via mobile questionnaires and a smartphone application over a two-week period. <h3>Design</h3> Repeated measures design. <h3>Setting</h3> Community. <h3>Participants</h3> Adults with a self-reported history of TBI (n=52; n=12 mild TBI [mTBI] without loss of consciousness [LOC], n=22 mTBI with LOC, n=18 moderate-to-severe TBI). <h3>Interventions</h3> N/A. <h3>Main Outcome Measures</h3> Measures of compliance (total number of completed assessments divided by number of scheduled assessments) for HRV and EMA. Participants instructed to complete HRV measures twice daily for 14 days. EMA conducted using the Behavioral Assessment Screening Tool Short Form (BAST-SF). Participants randomized to one of three study arms (Arm 1: BAST-SF sent every day at a scheduled time; Arm 2: BAST-SF sent every day at a random time; Arm 3: BAST-SF sent every other day at a scheduled time). <h3>Results</h3> Compliance with EMA calculated among all participants and within each study arm (n=17 in Arm 1, n=18 in Arm 2, n=17 in Arm 3). Participants completed 496 of 609 scheduled assessments (81.4%). For "completers" (completed >2 daily measures; n=44), participants completed 494 of 511 scheduled assessments (96.7%). Among all participants and completers, those in Arm 1 demonstrated the least compliance (79.4% and 89.0%), while those in Arm 3 demonstrated the most compliance (86.6% and 98.1%). Compliance with HRV measures calculated among all participants and by injury severity. Participants completed 1055 of 1456 scheduled HRV measures (72.5%). For "completers" (completed ≥ 1 HRV measure; n=44), participants completed 1055 of 1232 scheduled HRV measures (85.6%). Among all participants and completers, those with a mTBI with LOC demonstrated the least compliance (55.8% and 81.9%). Those with a moderate-to-severe TBI (among all participants) and those with a mTBI without LOC (among completers) demonstrated the most compliance (84.9% and 91.9%). <h3>Conclusions</h3> HRV and EMA via smartphone demonstrates initial feasibility and compliance among adults with TBI. This presents an opportunity for long-term monitoring and pairing of neurobehavioral and physiological symptom post-TBI, potentially leading to more personalized clinical interventions. <h3>Author(s) Disclosures</h3> NIH/NICHD R03HD094445.

Enhanced detection of abnormalities in heart rate variability and dynamics by 7-day continuous ECG monitoring.

BackgroundThe analysis of heart rate variability (HRV) and heart rate (HR) dynamics by Holter ECG has been standardized to 24 hs, but longer‐term continuous ECG monitoring has become available in clinical practice. We investigated the effects of long‐term ECG on the assessment of HRV and HR dynamics.MethodsIntraweek variations in HRV and HR dynamics were analyzed in 107 outpatients with sinus rhythm. ECG was recorded continuously for 7 days with a flexible, codeless, waterproof sensor attached on the upper chest wall. Data were divided into seven 24‐h segments, and standard time‐ and frequency‐domain HRV and nonlinear HR dynamics indices were computed for each segment.ResultsThe intraweek coefficients of variance of HRV and HR dynamics indices ranged from 2.9% to 26.0% and were smaller for frequency‐domain than for time‐domain indices, and for indices reflecting slower HR fluctuations than faster fluctuations. The indices with large variance often showed transient abnormalities from day to day over 7 days, reducing the positive predictive accuracy of the 24‐h ECG for detecting persistent abnormalities over 7 days. Conversely, 7‐day ECG provided 2.3‐ to 6.5‐fold increase in sensitivity to detect persistent plus transient abnormalities compared with 24‐h ECG. It detected an average of 1.74 to 2.91 times as many abnormal indices as 24‐h ECG.ConclusionsLong‐term ECG monitoring increases the accuracy and sensitivity of detecting persistent and transient abnormalities in HRV and HR dynamics and allows discrimination between the two types of abnormalities. Whether this discrimination improves risk stratification deserves further studies.

Monitoring stress and allostatic load in first responders and tactical operators using heart rate variability: a systematic review

BackgroundAwareness of the cumulative stress placed on first responders and tactical operators is required to manage acute fatigue, which can impair occupational performance, and may precipitate negative chronic health outcomes. The aim of this review was to investigate the utility of heart rate variability (HRV) to monitor stress and allostatic load among these populations.MethodsA systematic search of Academic Search Complete, MEDLINE complete, PsycINFO, SPORTDiscus and Scopus databases was conducted. Eligibility criteria: original peer reviewed research articles, written in English, published between 1985 and 2020, using human participants employed as a first responder or tactical operator, free from any psychological disorder.ResultsOf the 360 articles screened, 60 met the inclusion criteria and were included for full text assessment. Articles were classified based on single or repeated stressor exposure and the time of HRV assessment (baseline, during stressor, post stressor). Singular stressful events elicited a reduction in HRV from baseline to during the event. Stressors of greater magnitude reduced HRV for extended durations post stressor. Lower resting HRV was associated with lower situational awareness and impaired decision-making performance in marksmanship and navigation tasks. There were insufficient studies to evaluate the utility of HRV to assess allostatic load in repeated stressor contexts.ConclusionA reduction in HRV occurred in response to acute physical and cognitive occupational stressors. A slower rate of recovery of HRV after the completion of acute occupational stressors appears to occur in response to stressors of greater magnitude. The association between lower HRV and lower decision-making performance poses as a useful tool but further investigations on within subject changes between these factors and their relationship is required. More research is required to investigate the suitability of HRV as a measure of allostatic load in repeated stress exposures for fatigue management in first responder and tactical operators.

Decreased nocturnal heart rate variability and potentially related brain regions in arteriosclerotic cerebral small vessel disease

BackgroundTo assess heart rate variability (HRV) among patients with arteriosclerotic cerebral small vessel disease (CSVD) by comparing with control subjects, and to determine whether HRV parameters were related to structural alterations in brain regions involved in autonomic regulation among CSVD patients.MethodsWe consecutively recruited subjects aged between 50 and 80 years who visited the Stroke Prevention Clinic of our hospital and have completed brain magnetic resonance imaging examination from September 1, 2018 to August 31, 2019. Polysomnography and synchronous analyses of HRV were then performed in all participants. Multivariable binary logistic regression was used to identify the relationship between HRV parameters and CSVD. Participants were invited to further undergo three-dimensional brain volume scan, and the voxel based morphometry (VBM) analysis was used to identify gray matter atrophy.ResultsAmong 109 participants enrolled in this study, 63 were assigned to the arteriosclerotic CSVD group and 46 to the control group. Lower standard deviation of normal-to-normal intervals (SDNN, OR = 0.943, 95% CI 0.903 to 0.985, P = 0.009) and higher ratio of low to high frequency power (LF/HF, OR = 4.372, 95% CI 1.033 to 18.508, P = 0.045) during the sleep period were associated with CSVD, independent of traditional cerebrovascular risk factors and sleep disordered breathing. A number of 24 CSVD patients and 21 controls further underwent three-dimensional brain volume scan and VBM analysis. Based on VBM results, SDNN during the awake time (β = 0.544, 95% CI 0.211 to 0.877, P = 0.001) and the sleep period (β = 0.532, 95% CI 0.202 to 0.862, P = 0.001) were both positively related with gray matter volume within the right inferior frontal gyrus only among CSVD patients.ConclusionsDecreased nocturnal HRV is associated with arteriosclerotic CSVD independent of traditional cerebrovascular risk factors and sleep disordered breathing. The structural atrophy of some brain regions associated with cardiac autonomic regulation sheds light on the potential relationship.Trial registrationTrial registration number: ChiCTR1800017902. Date of registration: 20 Aug 2018.

Effects of low-frequency noise from wind turbines on heart rate variability in healthy individuals

Wind turbines generate low-frequency noise (LFN, 20–200 Hz), which poses health risks to nearby residents. This study aimed to assess heart rate variability (HRV) responses to LFN exposure and to evaluate the LFN exposure (dB, LAeq) inside households located near wind turbines. Thirty subjects living within a 500 m radius of wind turbines were recruited. The field campaigns for LFN (LAeq) and HRV monitoring were carried out in July and December 2018. A generalized additive mixed model was employed to evaluate the relationship between HRV changes and LFN. The results suggested that the standard deviations of all the normal to normal R–R intervals were reduced significantly, by 3.39%, with a 95% CI = (0.15%, 6.52%) per 7.86 dB (LAeq) of LFN in the exposure range of 38.2–57.1 dB (LAeq). The indoor LFN exposure (LAeq) ranged between 30.7 and 43.4 dB (LAeq) at a distance of 124–330 m from wind turbines. Moreover, households built with concrete and equipped with airtight windows showed the highest LFN difference of 13.7 dB between indoors and outdoors. In view of the adverse health impacts of LFN exposure, there should be regulations on the requisite distances of wind turbines from residential communities for health protection.

Analysis of heart rate variability in corn snakes (Pantherophis guttatus)

The assessment of heart rate variability (HRV) by linear methods in conjunction with Poincaré plots can be useful for evaluating cardiac regulation by the autonomic nervous system and for the diagnosis and prognosis of heart disease in snakes. In this report, we describe an analysis of HRV in conscious adult corn snakes Pantherophis guttatus (P. guttatus). The electrocardiogram (ECG) parameters were determined in adult corn snakes (8 females, 13 males) and used for HRV analysis, and the RR interval was analyzed by linear methods in the time and frequency domains. There was no sex-related difference in heart rate. However, significant differences were seen in the duration of the P, PR, and T waves and QRS complex; there was no difference in the QT interval. The values for the RR interval varied by 15.3% and 18.8% in male and female snakes, respectively, and there was considerable variation in the values for the high and low frequency domains. The changes in the time domain were attributed to regulation by the parasympathetic branch of the autonomic nervous system, in agreement with variations in the high and low frequency domains. The values for standard deviations 1 and 2 in Poincaré plots, as well as the values of the frequency domain, provide useful parameters for future studies of cardiac function in P. guttatus.

Short-term heart rate variability in resting conditions: methodological considerations.

Low values on heart rate variability (HRV) derived parameters at resting have been used to predict cardiovascular diseases (CVD) and mortality. In this regard, short-term HRV recordings (usually from 5 to 15 minutes) are increasing their popularity because data acquisition can be performed under more controlled conditions than long-term recordings (e.g., 24 hours). However, different methodological aspects before, during, and after the HRV assessment could affect the quantification and the clinical interpretations of the HRV-derived parameters, as well as hamper comparisons across different studies. In the present study, we summarize these methodological aspects that should be considered in both the research and the clinical settings. These are: (1) the validity and reproducibility of the device used to assess the HRV; (2) the influence of the software used to perform the artefact correction; (3) previous conditions before the testing day; (4) establishing the proper conditions during the HRV assessment (e.g., controlled respiratory frequency); (5) after assessing the HRV, considering the "best" data selection and statistical analysis approach; and (6) the role of the heart rate on the associations between the different CVD risk factors outcomes (e.g., cardiorespiratory fitness) and the HRV-derived parameters.

Heart Rate Variability in Adults with Sickle Cell Anemia During a Multitasking Field Test

Background: The integrity of the autonomic nervous system (ANS) is essential for keeping physiological processes stable, even under stress. Since there is growing interest in heart rate variability (HRV) analysis for the noninvasive assessment of the ANS in sickle cell anemia (SCA) patients, we studied the behavior of the ANS in the presence of a stressor that simulates daily-life multitasking, the Glittre ADL test (GA-T). Objectives: To evaluate the involvement of the ANS using HRV in adults with SCA during the GA-T and to quantify the strength of the correlation of HRV with lung and muscle functions. Methods: In this cross-sectional study, 16 adults with SCA and 12 healthy controls without sickle cell disease underwent HRV assessment during the GA-T, pulmonary function tests (spirometry, diffusing capacity for carbon monoxide (DLCO), and respiratory muscle testing). Peripheral muscle function [handgrip strength (HGS) and quadriceps strength (QS)] were also measured. Results: Compared to the healthy controls, adults with SCA showed lower HRV, with worse parasympathetic modulation due to reductions in the following indices: the root-mean-square difference of successive normal iRRs (iRR) (RMSSD); the percentage of pairs of consecutive iRRs whose difference is &gt; 50 m (pNN50); the high-frequency component of heart rate variability (HF); and the standard deviation of instantaneous beat-to-beat variability (SD1) (P &lt; 0.001 for all). Compared to healthy controls, individuals with SCA showed greater sympathovagal imbalance (higher ratio between low-frequency and HF components) and lower complexity of the ANS (lower approximate entropy). The GA-T time was correlated with parasympathetic activity indices: RMSSD (rs = -0.650, P &lt; 0.01); pNN50 (rs = -0.932, P &lt; 0.0001), HF (rs = -0.579, P &lt; 0.01), and SD1 (rs = -0.814, P &lt; 0.0001). Correlations between parasympathetic activity indices and DLCO, HGS, and QS measures were also significant. Conclusions: Adults with SCA have low HRV, with low parasympathetic activity, sympathovagal imbalance, and abnormal ANS complexity. In addition, lower HRV is associated with longer GA-T time, greater impairment of pulmonary diffusion, and greater muscle strength dysfunction.

Stress resistance and adaptive capacities of cardiovascular system of graduating teenagers with different level of studying load

The analysis of stress resistance and adaptive reactions of cardiovascular system was conducted according to the level of heart rate variability of graduating teenagers regardless of their studying load. The survey was held in Dnipro (Ukraine) based on a method of anonymous questioning using a personally developed and standardized questionnaire. 84 teenagers that are students of the 11th form of comprehensive schools and lyceums were asked. 22 children of relevant age from different countries made up a comparison group, among them an online survey was conducted by means of similar English-language questionnaire in Google-form. The assessment of heart rate variability of 46 graduates was given, using a cloud technology of automated interpretation of ECG (PRECISE). Statistical processing was conducted using the application program Statistica 6.0 for Windows. Decreasing of stress resistance and significant violations of adaptive cardiovascular reactions in teenagers of graduating classes in Dnipro was set, especially in lyceum students as a result of insufficient rest of students. During the educational period significant violation of adaptive capabilities takes place in 65.6 % of lyceum students: exhausting of functional organism’s reserves with decline in RMSSD to (17.2±1.9) meters per second, Total power to (607.25±11.9) meters per second has been observed in half of the students. At the same time, 85.3 % of the comprehensive school students have sufficient adaptive and worse resource capacities of an organism. For the first time it was highlighted that the autonomous nervous system among the examined teenagers operates in the imbalance regime of its sympathetic and parasympathetic link with a prevalence of sympathicotonia among the 50 % of lyceum students during a recessional period, 56.3 % during an educational period, while vagotonia and eutonia prevail among the comprehensive school students, not depending on the school year period. It was found out that physical activity promoted increased body resistance to stress factors. The efficient determination of heart rhythm variability (PRECISE diagnostics) was proven to control the functional state and adaptive capabilities of graduates’ cardiovascular system.

Bispectral Analysis of Heart Rate Variability to Characterize and Help Diagnose Pediatric Sleep Apnea.

Pediatric obstructive sleep apnea (OSA) is a breathing disorder that alters heart rate variability (HRV) dynamics during sleep. HRV in children is commonly assessed through conventional spectral analysis. However, bispectral analysis provides both linearity and stationarity information and has not been applied to the assessment of HRV in pediatric OSA. Here, this work aimed to assess HRV using bispectral analysis in children with OSA for signal characterization and diagnostic purposes in two large pediatric databases (0–13 years). The first database (training set) was composed of 981 overnight ECG recordings obtained during polysomnography. The second database (test set) was a subset of the Childhood Adenotonsillectomy Trial database (757 children). We characterized three bispectral regions based on the classic HRV frequency ranges (very low frequency: 0–0.04 Hz; low frequency: 0.04–0.15 Hz; and high frequency: 0.15–0.40 Hz), as well as three OSA-specific frequency ranges obtained in recent studies (BW1: 0.001–0.005 Hz; BW2: 0.028–0.074 Hz; BWRes: a subject-adaptive respiratory region). In each region, up to 14 bispectral features were computed. The fast correlation-based filter was applied to the features obtained from the classic and OSA-specific regions, showing complementary information regarding OSA alterations in HRV. This information was then used to train multi-layer perceptron (MLP) neural networks aimed at automatically detecting pediatric OSA using three clinically defined severity classifiers. Both classic and OSA-specific MLP models showed high and similar accuracy (Acc) and areas under the receiver operating characteristic curve (AUCs) for moderate (classic regions: Acc = 81.0%, AUC = 0.774; OSA-specific regions: Acc = 81.0%, AUC = 0.791) and severe (classic regions: Acc = 91.7%, AUC = 0.847; OSA-specific regions: Acc = 89.3%, AUC = 0.841) OSA levels. Thus, the current findings highlight the usefulness of bispectral analysis on HRV to characterize and diagnose pediatric OSA.

Associations Of Domain-specific Sedentary Time And Physical Activity With Heart Rate Variability In Women

PURPOSE: Growing evidence suggests that associations of sedentary time (ST) or physical activity (PA) with cardiovascular health may differ by domain (leisure vs. occupational). We examined associations between leisure and occupational ST and PA with heart rate variability (HRV) in women. METHODS: Cross-sectional data were obtained at the Pregnancy Outcomes and Community Health Study follow-up exam (POUCHmoms) which occurred 7 to 15 years after the study pregnancy. Women (n = 522; age = 37.7 ± 5.7 yr; 59% white) who self-reported leisure and occupational ST and PA (hours/day) using the Modifiable Activity Questionnaire and had a valid HRV assessment were included in the analysis. Five minutes of resting HRV (average heart rate, standard deviation of normal R-R intervals [SDNN], root mean square of successive differences [RMSSD], and high frequency [HF]) were calculated from seated ECG data using Kubios software. All HRV indexes were natural log (ln) transformed due to skewness. Progressive generalized linear mixed models evaluated associations of leisure and occupational ST and PA with HRV while adjusting for potential confounders (demographics and health-related factors) [Model 1], and mediators (clinical variables) [Model 2]. RESULTS: In Model 1, higher leisure ST was associated with greater HR, lower lnSDNN, and lower lnRMSSD indicating unfavorable HRV (Table 1). After adjusting for mediators (Model 2), higher leisure ST remained associated with greater HR, but other associations were attenuated. Higher leisure PA was associated with higher lnSDNN, lnRMSSD, and lnHF in all models. Occupational ST and PA were not associated with HRV. CONCLUSION: Associations between ST and PA with HRV appeared to differ by activity domain. Decreasing ST and increasing PA during leisure time are potential behavioral targets to improve HRV in women.Table 1: Associations between leisure and occupational ST and PA with heart rate and HRV (n = 522)

Persistent homology as a new method of the assessment of heart rate variability.

Heart rate variability (hrv) is a physiological phenomenon of the variation in the length of the time interval between consecutive heartbeats. In many cases it could be an indicator of the development of pathological states. The classical approach to the analysis of hrv includes time domain methods and frequency domain methods. However, attempts are still being made to define new and more effective hrv assessment tools. Persistent homology is a novel data analysis tool developed in the recent decades that is rooted at algebraic topology. The Topological Data Analysis (TDA) approach focuses on examining the shape of the data in terms of connectedness and holes, and has recently proved to be very effective in various fields of research. In this paper we propose the use of persistent homology to the hrv analysis. We recall selected topological descriptors used in the literature and we introduce some new topological descriptors that reflect the specificity of hrv, and we discuss their relation to the standard hrv measures. In particular, we show that this novel approach provides a collection of indices that might be at least as useful as the classical parameters in differentiating between series of beat-to-beat intervals (RR-intervals) in healthy subjects and patients suffering from a stroke episode.

Use of the Polar V800 and Actiheart 5 heart rate monitors for the assessment of heart rate variability (HRV) in horses

Heart rate variability (HRV) is a commonly used metric in animal science to quantify an aspect of the physiological response to stressors. HRV analysis relies upon accurate detection of the electrical activity of the heart to define inter-beat interval (IBI). In horses, this can be problematic due to specific features of the equine ECG waveform and a high incidence of 2nd-degree atrioventricular (AV) block in clinically normal horses at rest.The current study validates the collection and interpretation of IBI data from two heart rate monitors (HRMs) principally designed for human personal monitoring (Polar V800 and Actiheart 5). 30 min of synchronous IBI data was collected using the two HRMs and a 4-lead telemetric ECG that is widely used in equine veterinary clinical practice (Televet 100). The study was conducted using a mixed sample (n = 17) of general riding horses, with (n = 4) and without (n = 13) cardiac dysrhythmias. HRV data was derived from each IBI data set and compared following application of a series of correction factors.There was a very strong inter-class correlation of HRV parameters from both the Actiheart 5 and Polar V800 with the Televet 100 data. Both HRMs providing an acceptable level of agreement with both time and frequency domain HRV parameters. The data from the Actiheart 5 were found to be interchangeable with the Televet 100 in respect of beat detection whereas the Polar V800 data required a 0.4 s artefact correction to give best agreement. Both HRMs have utility in equine research for demonstrating the direction and magnitude of change in HRV parameters, although users must apply appropriate artefact correction to maximise data validity.