Standard Deviation Of NN Intervals Research Articles

Comparison of Heart Rate Variability in Thai Older Adults with Hypertension, Pre-Hypertension, and Normotension.

This study aims to compare HRV variables across three cohorts: normotensive (NT), prehypertensive (pre-HT), and hypertensive (HT) and to assess the relationship between the blood pressure (BP) and HRV parameters. Employing a cross-sectional design, 64 older participants were categorized based on the Joint National Committee's criteria into NT (n = 10), pre-HT (n = 33), and HT (n = 21) groups. Anthropometric data, lipid profiles, and HRV indices were evaluated. HRV data were obtained from the Polar V800 chest strap device using HRV Kubios software for data analysis of short-term recordings lasting 10 minutes. This analysis encompasses both time and frequency domain assessments. The time domain includes the standard deviation of NN intervals (SDNN), the root mean square of successive RR interval differences (RMSSD), and the percentage of successive RR intervals differing by over 50 ms (pNN50). The frequency domain includes low frequency (LF), high frequency (HF), and the ratio of LF-to-HF power (LF/HF). Data were statistically analyzed via one-way analysis of variance (ANOVA) and Pearson correlation. The HT group exhibited significantly lower values in SDNN, pNN50, LF power, and HF power in comparison to the NT group (P < 0.05). Moreover, the HT group had a significantly lower SDNN value compared to the pre-HT group (P < 0.05). Inverse associations were uncovered between systolic and diastolic blood pressure and SDNN, pNN50, and HF power (P < 0.05). Multiple regression further highlighted the significance of systolic and pulse pressure concerning HF power (P < 0.05). HRV indices are reduced in Thai older adults with HT compared with those with NT. Monitoring HRV in older adults can provide valuable insights into autonomic function and cardiovascular disease risk.

Analysis of the Relationship between Recent Small Subcortical Infarcts and Autonomic Nervous Dysfunction.

Autonomic Nervous System (ANS) dysfunction may be involved in the pathogenesis of Cerebral Small Vessel Disease (CSVD). The study aimed to explore the relationship between Recent Small Subcortical Infarct (RSSI) and Blood Pressure Variability (BPV), and Heart Rate Variability (HRV). A total of 588 patients from the CSVD registration research database of Henan Province were included in this study, and were divided into two groups according to the presence of RSSI. Clinical data, including demographic characteristics, disease history, laboratory indexes, 24-hour ambulatory blood pressure and electrocardiogram indicators, and imaging markers of CSVD, were collected. Univariate and binary logistic regression analyses were used to study the relationship between RSSI and indicators of laboratory, HRV and BPV in the CSVD population. Multivariate analysis showed that higher 24-hour mean Diastolic Blood Pressure (DBP)[Odds Ratios (OR)=1.083,95% Confidence Intervals (CI)=(1.038,1.129), p < 0.001], Standard Deviation (SD) of 24-hour DBP [OR=1.059,95%CI=(1.000,1.121), p = 0.049], nocturnal mean Systolic Blood Pressure (SBP) [OR=1.020,95%CI=(1.004,1.035), p = 0.012], nocturnal mean DBP [OR=1.025,95%CI=(1.009,1.040), p = 0.002] were independent risk factors for RSSI. In contrast, the decrease of the standard deviation of N-N intervals (SDNN) [OR=0.994,95%CI=(0.989,1.000), p = 0.035] was beneficial to the occurrence of RSSI. In addition, neutrophil counts [OR=1.138,95%CI=(1.030,1.258), p = 0.011], total cholesterol (TC) [OR=1.203,95%CI=(1.008,1.437), p = 0.041] and High-Density Lipoprotein (HDL) [OR=0.391, 95%CI=(0.195,0.786), p = 0.008] were also independently associated with the occurrence of RSSI. After adjusting for confounding factors, except for TC, the other factors remained associated with the occurrence of RSSI. Increased 24-hour mean DBP, nocturnal mean SBP and DBP, SD of 24-hour DBP and decreased SDNN were independently correlated with RSSI occurrence, suggesting that sympathetic overactivity plays a role in the pathogenesis of RSSI.

A Prebiotic Diet Increases Cardiovascular Adaptability Under Hypergravity-Induced Stress

Life in space presents significant challenges to mammalian physiology and the longer one is in space, the greater the impact. Three major stressors are present in space: 1) changes in gravitational environment, 2) psychological/physiological stress, and 3) constant low dose radiation. It is critical, therefore, to discover interventions that promote stress resilience. Dietary prebiotics selectively increase the relative abundances of probiotic bacterial species in the gut. We have previously reported that a diet enriched in galactooligosaccharide (GOS) and polydextrose (PDX) compared to control diet robustly elevates parabacteroides distasonis, clostridium leptum, and reduces the negative impact of acute and chronic stress. Interoceptors (e.g., baroreceptors) sense gravity-induced changes in blood pressure and cardiac function/structure. There is evidence that hypergravity disrupts autonomic and cardiovascular homeostasis and function. Cardiovascular homeostasis depends on a sympathetic and parasympathetic balance reflected in heart rate variability (HRV), a measure of cardiovascular stress. The following study was designed to test the hypothesis that GOS+PDX reduces the cardiovascular impacts of living in an altered gravitational environment. Adult female mice were housed in 1G or 3G and were fed GOS+PDX or a matched control diet for 4 weeks on the NASA Ames 1.22-meter radius centrifuge. We recorded electrocardiograms (ECG) in animals from all four groups immediately before, halfway through, and immediately after centrifugation. We analyzed HRV data using a Python-based Jupyter notebook and R. R was used to perform a 1F-LD-1F ANOVA with pair-wise comparisons to quantify changes in HRV longitudinally. Classic time domain based HRV metrics, standard deviation of the successive differences between adjacent R-R intervals and standard deviation of NN intervals, showed little change over time. Instead, frequency domain measures showed results were housing in 3G compared to 1G reliably changed Shannon entropy, Sample entropy, and low to high frequency ratio at each time-point. The changes across time reflected adaptation to hypergravity and a consequent reduction in HRV. Poincare plot analysis and low to high frequency ratio metrics showed divergent compensatory reactions between diets at 3G. Overall, 3G impacted HRV less in mice that were fed the prebiotic diet compared to the control diet. Further longitudinal studies with greater temporal resolution are needed to assess changes in HRV caused by gravitational changes. However, our data suggests the prebiotic diet significantly reduces 3G activation of sympathetic drive and increases parasympathetic drive, potentially reducing cardiovascular stress in animals exposed to high gravity. NASA grant 80NSSC19K1038 funded this project. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Can an intervention integrating sports and medicine improve children's health more effectively? Monitoring based on sleep, body mass index, and heart rate variability.

Theoretical studies have suggested that the integration of sports and medicine with one another could positively affect children's health. By monitoring the variation characteristics of children's sleep, body mass index (BMI), and heart rate variability (HRV), we explored and compared the influences of and differences between two interventions - physical exercise and an intervention integrating sports and medicine - on improving children's health. We conducted a randomised controlled study, where we randomly divided 136 children into the physical exercise group (PEG), the integration of sports and medicine group (ISMG), and the control group. We measured sleep, BMI, and HRV at baseline and week eight. After the eight-week intervention, the sleep scores in the PEG and the ISMG were significantly lower than in the control group, while the scores in the ISMG were significantly lower than in the PEG. After the eight-week intervention, the BMI of both the PEG and the ISMG was significantly lower than that of the control group, without a significand difference between the two intervention groups. After the eight-week intervention, the standard deviation of normal-to-normal intervals (SDNN), root mean square differences of the standard deviation (RMSSD), low-frequency of normal (LFn), and high-frequency of normal (HFn) in the PEG and the ISMG were significantly higher than those in the control group, again without a significant difference between the two intervention groups. After intervention, sleep, BMI, and HRV of the three groups were correlated with one another to different degrees, but the correlation coefficient of the two exercise groups was higher. Based on the interventions, we observed a significant correlation between sleep, BMI, and HRV in children. Regular physical exercise or an intervention integrating sports and medicine could synergistically improve sleep, BMI, and HRV in this population, with the latter having a better effect on improving sleep quality.

The Impact of Prenatal Alcohol Exposure on the Autonomic Nervous System and Cardiovascular System in Rats in a Sex-Specific Manner.

Fetal Alcohol Spectrum Disorder (FASD) is a consequence of prenatal alcohol exposure (PAE) associated with a range of effects, including dysmorphic features, prenatal and/or postnatal growth problems, and neurodevelopmental difficulties. Despite advances in treatment methods, there are still gaps in knowledge that highlight the need for further research. The study investigates the effect of PAE on the autonomic system, including sex differences that may aid in early FASD diagnosis, which is essential for effective interventions. During gestational days 5 to 20, five pregnant female Wistar rats were orally administered either glucose or ethanol. After 22 days, 26 offspring were born and kept with their mothers for 21 days before being isolated. Electrocardiographic recordings were taken on the 29th and 64th day. Heart rate variability (HRV) parameters were collected, including heart rate (HR), standard deviation (SD), standard deviation of normal-to-normal intervals (SDNN), and the root mean square of successive differences between normal heartbeats (RMSSD). Additionally, a biochemical analysis of basic serum parameters was performed on day 68 of the study. The study found that PAE had a significant impact on HRV. While electrolyte homeostasis remained mostly unaffected, sex differences were observed across various parameters in both control and PAE groups, highlighting the sex-specific effects of PAE. Specifically, the PAE group had lower mean heart rates, particularly among females, and higher SDNN and RMSSD values. Additionally, there was a shift towards parasympathetic activity and a reduction in heart rate entropy in the PAE group. Biochemical changes induced by PAE were also observed, including elevated levels of alanine transaminase (ALT) and aspartate aminotransferase (AST), especially in males, increased creatinine concentration in females, and alterations in lipid metabolism. PAE negatively affects the development of the autonomic nervous system, resulting in decreased heart rate and altered sympathetic activity. PAE also induces cardiovascular abnormalities with sex-specific effects, highlighting a relationship between PAE consequences and sex. Elevated liver enzymes in the PAE group may indicate direct toxic effects, while increased creatinine levels, particularly in females, may suggest an influence on nephrogenesis and vascular function. The reduced potassium content may be linked to hypothalamus-pituitary-adrenal axis overactivity.

Psychological Stress Analysis to Evaluate the Effects of Transcranial Magnetic Stimulation on Mood Regulation and Quality of Life in Patients with Bipolar Disorder.

To explore the impact of transcranial magnetic stimulation on emotion regulation and quality of life in patients with bipolar disorder (BD) and to evaluate the effectiveness of the mental stress analyzer. Patients with BD admitted to our hospital from August 2022 to August 2023 were retrospectively selected. For the present study, 60 patients who received drug therapy served as the control group, and the other 60 patients who received repeated transcranial stimulation on this basis served as the observation group. The heart rate variability (HRV) of the two groups of patients was detected by a mental stress analyzer/HRV analysis system. Hamilton Depression Rating Scale (HAMD), Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS) were used to evaluate the mental state of the two groups of patients. The quality of life of the two groups was assessed using the Comprehensive Quality of Life Questionnaire 74 (GQOLI-74). Clinical effectiveness global rating scale-illness severity (CGI-SI) was used to evaluate the clinical symptoms of the two groups of patients, and the incidence of adverse reactions was calculated. In comparison to the control group, the high-frequency power (HF) of the patients demonstrated an elevation in the observation group, and the low-frequency power (LF) and LF/HF were significantly reduced (p < 0.05). The standard deviation of NN intervals (SDNN), standard deviation of all five-minute NN intervals (SDANN), root mean square of successive differences (rMSSD), and percent RR intervals with a difference in duration higher than 50 ms (PNN50) of patients in the observation group showed a notable increase compared to the control group (p < 0.05). Compared with the control group, the HAMD, SAS, and SDS scores of the patients in the observation group demonstrated a substantial decline relative to the control group (p < 0.05). In contrast to the control group, there was a significant increase in the overall clinical effectiveness rate among patients in the observation group, and the incidence of adverse reactions was significantly reduced (p < 0.05). Repetitive transcranial magnetic stimulation (rTMS) has significant clinical effects in treating BD and can effectively improve patients' anxiety, suppress emotions, and regulate patients' emotions. At the same time, rTMS has high safety and little impact on the balance of patients' autonomic nervous function, reduces the incidence of adverse reactions, accelerates the patient's recovery process, and is suitable for clinical promotion.

Continuous Long-Term Assessment of Heart Rate Variability in Adults with Cyanotic Congenital Heart Disease after Surgical Repair.

Background: Heart rate variability (HRV) is an established, non-invasive parameter for the assessment of cardiac autonomic nervous activity and the health status in general cardiology. However, there are few studies on HRV in adults with congenital heart defects (CHDs). The aim of the present study was to evaluate the use of long-term continuous HRV measurement for the assessment of global health status in adults with cyanotic CHD. Methods: This prospective study included 45 adults (40% female, mean age = 35.2 ± 9.2 [range: 19-58] years) after cardiac surgical repair. HRV parameters were calculated from continuous 24 h measurements using a Bittium Faros 180 sensor (Bittium Corp., Oulu, Finland). Results: Postoperative patients with transposition of the great arteries (TGA) (n = 18) achieved significantly higher values of standard deviation of NN intervals (SDNN) (175.4 ± 59.9 ms vs. 133.5 ± 40.6 ms; p = 0.013) compared with patients with other conotruncal anomalies (n = 22). Comparing patients with TGA after a Senning-Brom or Mustard operation (n = 13) with all other heart surgery patients (n = 32), significantly higher HRV parameters were found after atrial switch (root mean square of successive RR interval differences: 53.6 ± 20.7 ms vs. 38.4 ± 18.3 ms; p = 0.019; SDNN: 183.5 ± 58.4 ms vs. 136.3 ± 45.3 ms; p = 0.006). A higher SDNN was also measured after Senning-Brom or Mustard operations than after a Rastelli operations (n = 2) (SDNN: 183.5 ± 58.4 ms vs. 84.5 ± 5.2 ms; p = 0.037). When comparing atrial switch operations (n = 3) with Rastelli operations, the SDNN value was significantly shorter in the Rastelli group (p = 0.004). Conclusions: Our results suggest that continuous HRV monitoring may serve as a marker of cardiac autonomic dysfunction in adults with cyanotic CHD after surgical repair. Impaired cardiac autonomic nervous activity may be associated with an increased risk of adverse reactions in patients with repaired CHD. Therefore, a longitudinal assessment of HRV patterns and trends may provide a deeper insight into dynamic changes in their autonomic regulation and disease progression, lifestyle changes, or treatments. As each person has individual variability in heart rate, HRV may be useful in assessing intra-individual disease progression and may help to improve personalized medicine. Further studies are needed to better understand the underlying mechanisms and to explore the full potential of HRV analysis to optimize medical care for ACHDs.

Changes in heart rate variability over time from symptom onset of transient global amnesia

Transient global amnesia (TGA) often involves precipitating events associated with changes in autonomic nervous system (ANS), and heart rate variability (HRV) reflects the ANS state. This study aimed to investigate HRV changes after TGA. A retrospective analysis of HRV included patients diagnosed with TGA between January 2015 and May 2020. The time and frequency domains of HRV were compared among three groups: early (< 1 week after TGA, n = 19), late (1–4 weeks after TGA, n = 38), and healthy control (HC, n = 19). The Pearson’s correlation between time and time-domain HRV was also examined. The standard deviation of NN intervals (SDNN) (early, 47.2; late, 35.5; HC, 41.5; p = 0.033) and root mean square of successive RR interval differences (RMSSD) (early, 38.5; late, 21.3; HC, 31.0; p = 0.006) differed significantly among the three groups. Post-hoc analysis showed statistically significant differences only in the early and late groups in both SDNN (p = 0.032) and RMSSD (p = 0.006) values. However, the frequency domain with total power, low-frequency and high-frequency powers, and low-frequency/high-frequency ratio did not differ. SDNN (Pearson correlation coefficient =− 0.396, p = 0.002) and RMSSD (Pearson correlation coefficient =− 0.406, p = 0.002) were negatively correlated with time after TGA. Changes in HRV occurred over time after the onset of TGA, with the pattern showing an increase in the first week and then a decrease within 4 weeks.

Heart rate variability and its association with symptoms of orthostatic hypotension in spinal cord injury

Context/objective To assess differences in autonomic function using heart rate variability (HRV) parameters between people with and without orthostatic hypotension (OH), and to determine symptoms of OH in people with spinal cord injury (SCI). Methods R-R interval and blood pressure (BP) data were recorded using Finometer PRO® in both the supine position and at a 60-degree tilt using a tilt table, each lasting for 6 minutes. R-R interval data were processed using the Kubios HRV analysis software to convert R-R interval into time and frequency domains for further analysis. Results Compared to the non-OH group, the SCI group with OH exhibited lower values for root mean square of the successive differences (RMSSD) and standard deviation of normal-to-normal interval (SDNN), along with an elevated heart rate during tilt-up. Participants with OH symptoms had a lower average heart rate in the supine and 60-degree positions compared to asymptomatic participants. Logistic regression analysis indicated that SDNN in the supine position correlated with the presence of OH, and that the mean heart rate in the 60-degree position was related to the presence of symptoms. Conclusions Differences in HRV parameters were observed in people with SCI and OH, suggesting a reduced parasympathetic activity in the supine position, likely as a response to maintain homeostasis in BP regulation. Despite the presence or absence of OH symptoms, there was no difference in HRV parameters. This finding suggests that autonomic function may not be the primary determinant of these symptoms, with other factors likely being more influential.

Unveiling the age-related dynamics in Sjögren's syndrome: Insights from heart rate variability and autonomic function.

Sjögren's Syndrome (SS), mainly affecting women in their midlife, is characterized by persistent inflammation in glands producing tears and saliva, often leading to significant complications. This study investigates the differences in autonomic system functioning between individuals with SS and healthy controls. From April 2019 to December 2022, 329 diagnosed primary SS (pSS) patients and 30 healthy controls were enrolled at Taipei Veterans General Hospital, Taipei, Taiwan. The study assessed autonomic nervous system functioning using various HRV metrics. Participants were divided based on age and AECG criteria, including salivary gland biopsy and autoantibody status. Significant differences in Heart Rate Variability (HRV) were observed between pSS patients and healthy controls. The total power index was notably lower in pSS patients (4.98 ± 1.29) than in controls (5.54 ± 1.21, p = .022). Additionally, Vagal (VAG) activity was significantly reduced in the pSS group (4.95 ± 1.33) compared to the healthy control group (5.47 ± 1.19, p = .041). Age-stratified analysis highlighted that the ≤50 years pSS group had a higher heart rate (77.74 ± 10.42) compared to the >50 years group (73.86 ± 10.35, p = .005). This group also showed a higher total power index (5.78 ± 1.30) versus the >50 years group (4.68 ± 1.19, p < .001), and significantly lower VAG activity (4.70 ± 1.26, p = .007) compared to healthy controls. Furthermore, the Standard Deviation of Normal-to-Normal Intervals (SDNN) was greater in the ≤50 years SS group (44.45 ± 37.12) than in the >50 years group (33.51 ± 26.18, p = .007). In pSS patients, those positive for both salivary gland biopsy and autoantibodies demonstrated a lower Total Power (4.25 ± 1.32) and R-wave validity (93.50 ± 4.79, p < .05) than other groups, suggesting more severe autonomic imbalance. The R-R interval variation (RRIV) was also significantly higher in this dual-positive group (696.10 ± 975.41, p < .05). Additionally, the ESSPRI for dryness was markedly higher in the dual-positive group (8.10 ± 1.45, p < .05), indicating more severe symptoms. These findings reveal significant variations in autonomic function in SS patients, especially in those with dual-positive biopsy and autoantibody status. This study demonstrates significant autonomic dysfunction in pSS patients compared to healthy controls, particularly in those positive for both salivary gland biopsy and autoantibodies. The age-stratified analysis further emphasizes the impact of aging on autonomic system functioning in pSS, suggesting a need for age-specific management approaches in pSS patient care.

Pulse rate variability and health-related quality of life assessment with the Short Form-8 Japanese version in the general Japanese population

We aimed to investigate the association between pulse rate variability (PRV) and health-related quality of life (HRQOL) in the general population. A cross-sectional study was conducted with 5908 Japanese men and women aged 30–79 years. PRV was assessed at rest using 5-min recordings of pulse waves with a photoplethysmographic signal from a fingertip sensor, and the time and frequency domains of PRV were determined. HRQOL was assessed with the Short Form-8 (SF-8) Japanese version, and poor HRQOL was defined as an SF-8 sub-scale score < 50. A test for nonlinear trends was performed with the generalized additive model with a smoothing spline adjusted for confounders. The lowest multivariable-adjusted odds ratios for poor physical component score were found in those who had second or third quartile levels of standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive difference (RMSSD), and high-frequency (HF) power and trended slightly upward in the higher levels. PRV-derived parameters were nonlinearly associated with poor physical component scores. In conclusion, reduced PRV-derived SDNN, RMSSD and HF power were associated with poor HRQOL in the domain of physical function. Higher levels of these parameters did not necessarily translate into better HRQOL.

Agreement of ultra-short-term heart rate variability measure after different repeated bouts of sprint ability tests.

This study aims to explore: (1) the validity of post-exercise ultra-short-term heart rate variability (HRVust) after two different bouts of repeated sprint ability test (RSA), and (2) the relationship between HRVust measure and RSA performance. Twenty adolescent male futsal players voluntarily participated in this study (age: 17.65 ± 1.81 years, body height: 170.88 ± 4.98 cm, body weight: 61.78 ± 4.67 kg). The participants performed a standard RSA test (RSAstandard) and an RSA test with a 10% decrement of the best sprint time test (RSA10%decrement) on two separate occasions within a week. On both occasions, a 5-min resting electrocardiography was administered pre- and post-RSA exercise protocols. The first 30-s (HRVust30s), 60-s (HRVust60s), and 60-120-s (HRVust1-2min) were extracted and used to compare with the standard of 5-min HRV recording (HRVcriterion). The natural logarithm (ln) of the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive normal-to-normal interval differences (RMSSD) HRV indices were utilised to establish intraclass correlation coefficient (ICC2,1), coefficient of variation (%CV), and Pearson product-moment correlation (r). Results revealed the ICC values of HRVust lnSDNN (RSAstandard = 0.77-0.88; RSA10%decrement = 0.41-0.71) and lnRMSSD (RSAstandard = 0.81-0.86; RSA10%decrement = 0.57-0.82). Furthermore, significantly positive correlations between best sprint time and post-exercise HRVust indices were found in lnSDNN (r = 0.47-0.62; p < 0.05) and lnRMSSD (r = 0.45; p < 0.05). Additionally, a large CV of lnSDNN (RSAstandard = 32%-45%; RSA10%decrement = 29%-39%), lnRMSSD (RSAstandard = 50%-66%; RSA10%decrement = 48%-52%), and ratio (RSAstandard = 45%-126%; RSA10%decrement = 27%-45%) was found after the RSA protocols. In conclusion, the number of bouts of RSA exercise potentially influences the agreement of post-exercise time-domain HRVust indices to standard HRV measure.

Assessing autonomic activity and prognostic risk factors comparing multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis.

In pediatric multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis, autonomic nervous system function can be evaluated by a non-invasive method called heart rate variability. This study aims to evaluate heart rate variability in these two groups by comparing them with each other. This is the first study assessing these values in these two groups of patients. Patients who are diagnosed with multisystem inflammatory syndrome in children and isolated viral myocarditis/myopericarditis at a university hospital from September 2021 to February 2023 are screened by electrocardiography, echocardiography, and 24-hour Holter monitoring. A healthy control group, compatible in age and gender with the patient groups, was selected from healthy subjects that applied to the hospital for palpitation, murmur, and/or chest pain. Heart rate variability parameters and related laboratory markers were analyzed and compared among the three groups. There were 30 patients with multisystem inflammatory syndrome in children, 43 patients with isolated viral myocarditis/myopericarditis, and 109 participants in the healthy control group. Statistically significant differences were found in most of the heart rate variability parameters: standard deviation of normal to normal intervals (SDNN), the mean of the 5- minute RR interval standard deviations (SDNNİ), the standard deviation of 5-minute R wave to R wave(RR) interval means (SDANN), the root mean square of successive RR interval differences (RMSSD), and the percentage of the beats with a consecutive RR interval difference of more than 50 ms (pNN50%), very low frequency, high frequency, low frequency, triangular index, and low frequency/high-frequency ratio. Multisystem inflammatory syndrome in children patients had impaired and declined heart rate variability values compared to the other two groups. In patients with myocarditis/myopericarditis, we couldn't find a significant difference in these parameters with the control group. Heart rate variability can be used as an important non-invasive autonomic function parameter in determining prognosis and treatment plans, especially in patients diagnosed with multisystem inflammatory syndrome in children. This impairment of autonomic activity could be more prominent in patients with decreased left ventricular systolic functions.

Heart Rate Variability Measured from Wearable Devices as a Marker of Disease Severity in Tetanus.

Tetanus is a disease associated with significant morbidity and mortality. Heart rate variability (HRV) is an objective clinical marker with potential value in tetanus. This study aimed to investigate the use of wearable devices to collect HRV data and the relationship between HRV and tetanus severity. Data were collected from 110 patients admitted to the intensive care unit in a tertiary hospital in Vietnam. HRV indices were calculated from 5-minute segments of 24-hour electrocardiogram recordings collected using wearable devices. HRV was found to be inversely related to disease severity. The standard deviation of NN intervals and interquartile range of RR intervals (IRRR) were significantly associated with the presence of muscle spasms; low frequency (LF) and high frequency (HF) indices were significantly associated with severe respiratory compromise; and the standard deviation of differences between adjacent NN intervals, root mean square of successive differences between normal heartbeats, LF to HF ratio, total frequency power, and IRRR, were significantly associated with autonomic nervous system dysfunction. The findings support the potential value of HRV as a marker for tetanus severity, identifying specific indices associated with clinical severity thresholds. Data were recorded using wearable devices, demonstrating this approach in resource-limited settings where most tetanus occurs.

Analysis of Heart Rate Variability in Young Male Adults with Depression and Anxiety during Warm-water Footbath

Abstract Background: Heart rate variability (HRV) modulates both the sympathetic nervous system and the parasympathetic nervous system (PNS) of the autonomic nervous system. Mood disorder is one of the contributing factors to influence HRV. The warm-water footbath as a relaxing way is used to enhance the PNS. In this study, we intended to explore the association between HRV and a footbath in the mood disorder group. Methods: We recruited 14 young male study participants to receive a 30-minute warm-water footbath three times a week. Furthermore, we monitored the heart rates electrocardiographically before, during, and after the intervention. Results: This study showed that the footbath not only significantly enhanced standard deviation of NN (SDNN) intervals, high-frequency (HF) power, and low-frequency (LF) power during the first five minutes footbath (p &lt; 0.01) but also increased all the parameters in five minutes after finishing the footbath. SDNN intervals, HF power, and LF power remained significantly upward in the next five minutes (p &lt; 0.05). Conclusion: In line with previous studies, this study showed that a footbath elevated the PNS-related HRV parameters. We suggest that a warm-water footbath improves the PNS modulation possibly through baroreflex. In addition, those with cardiac conditions and depression should be particularly attentive to their condition during and following a footbath.

Napping and heart rate variability in elite athletes.

Sleep and autonomic nervous system (ANS) influence each other in a bidirectional fashion. Importantly, it has been proposed that sleep has a beneficial regulatory influence over cardiovascular activity, which is mostly controlled by autonomic regulation through the activity of sympathetic and parasympathetic pathways of the ANS. A well-established method to non-invasively assess cardiac autonomic activity is heart rate variability (HRV) analysis. We aimed to investigate the effect of a 40-min nap opportunity on HRV. Twelve professional basketball players randomly accomplished two conditions: 40-min nap (NAP) and control (CON). Nocturnal sleep and naps were monitored by actigraphic recording and sleep diaries. Total sleep time (TST), time in bed (TIB), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) were analyzed. HRV was analyzed in 5-min segments during quiet wake before and after each condition with controlled breathing. Were analysed high (HF) and low frequency (LF) bands, the standard deviation of NN interval (SDNN), HRV index and stress index (SI). Wellness Hooper index and Epworth Sleepiness Scale (ESS) were assessed before and after both conditions. There was no significant difference in TIB, TST, SE, WASO, and VAS between NAP and CON. A significant increase in SDNN, HRV index, and LF and a significant decrease in HF, SI, ESS, and Hooper's stress and fatigue scores were observed from pre- to post-nap. In conclusion, napping reduces sleepiness, stress and fatigue, and might provide an advantage by preparing the body for a much-required sympathetic comeback following peaceful rest.

Associations between physical fitness, body composition, and heart rate variability during exercise in older people: exploring mediating factors.

Age-related changes in body composition affect physical fitness in older adults. However, whether the autonomic response is associated with body fat percentage and its implication for physical fitness is not fully understood. To understand the association between physical fitness, body composition, and heart rate variability in older people and its mediating factors. A cross-sectional study with 81 older adults was conducted, assessing Short Physical Performance Battery (SPPB), Two-minute Step Test (TMST), body composition, and cardiac autonomic response. Correlation and mediation analyses were performed. Body fat percentage negatively correlated with physical fitness (SPPB: r=-0.273, p=0.015; TMST: r=-0.279, p=0.013) and sympathetic activity (sympathetic nervous system (SNS) index: r=-0.252, p=0.030), yet positively correlated with parasympathetic tone (root mean square of successive differences (RMSSD): r=0.253, p=0.029; standard deviation of NN intervals (SDNN): r=0.269, p=0.020). Physical fitness associated with sympathetic nervous system index (SPPB: r=0.313, p=0.006; TMST: r=0.265, p=0.022) and parasympathetic nervous system index (TMST: r=-0.344, p=0.003). Muscle mass mediated body fat's impact on physical fitness, while physical fitness mediated body fat's impact on autonomic response. Body composition and cardiac autonomic response to exercise are associated with physical fitness in older people, highlighting a possible protective effect of muscle mass against the decline in physical fitness associated with increased body fat.

Relationship between dust allergen sensitization and cardiac autonomic function in patients with chronic obstructive pulmonary disease.

Cardiac autonomic function predicts cardiovascular disease risk. The aim of this study was to investigate the relationship between sensitization to dust allergens and cardiac autonomic dysfunction in patients with chronic obstructive pulmonary disease (COPD), and to provide new ideas for the prevention of cardiovascular complications in these patients. Immunoassays for sensitization to cats/dogs, cockroaches and dust mites were performed in 840 patients with COPD. Indicators of heart rate variability in these patients were used to assess cardiac autonomic function, including standard deviation of normal-to-normal intervals (SDNN), root-mean square of successive differences between normal-to-normal intervals (RMSSD), low-frequency power (LF), high-frequency power (HF), and LF/HF ratios, which were obtained based on ambulatory electrocardiographic monitoring data. The relationship between sensitization to these dust allergens and heart rate variability was explored using multivariate logistic regression. The multivariate analyses showed that sensitization to total allergens was associated with reduced levels of SDNN, RMSSD, LF and HF and with increased levels of the LF/HF ratio in the patients with COPD (p < .05). Dust allergen sensitization may be associated with cardiac autonomic dysfunction in patients with COPD. Whether desensitization can prevent cardiovascular complications in these patients should be further explored.

Influence of the method of manual-physical correction on autonomic regulation in patients with essential arterial hypertension

One of the methods of non-drug treatment of essential arterial hypertension, is manual, osteopathic effects on the spine, primarily the cervical spine. Despite the absence of these methods in clinical guidelines for essential arterial hypertension, they continue to develop and improve. One of the promising areas is manual-physical correction with an effect on the cervical spine and subsequent strengthening of the muscle corset with the help of physical exercises (method of A.Yu. Shishonin). One of the supposed mechanisms for reducing blood pressure (BP) in this case is the effect on the autonomic nervous system (ANS). In the course of the study, which was based on the study of heart rate variability (HRV), the presence of pronounced signs of a decrease in sympathetic influences and activation of the parasympathetic nervous system was shown. The parameters of statistical linear analysis (standard deviation of NN intervals; stress index, etc.) and the wave spectrum shifted towards sympathicotonia during therapy using the method of A.Yu. Shishonin. The HRV data were obtained against the background of a decrease in blood pressure and a decrease in heart rate (HR), which suggests the impact of manual physical correction on the ANS as one of the key mechanisms mediating its effect.

Impaired Cardiovagal Activity as a Link Between Hyperglycemia and Arterial Stiffness in Adults With Type 2 Diabetes Mellitus Among an Eastern Indian Population: A Cross-sectional Study

ObjectivesCardiac autonomic neuropathy (CAN) is one of the most common yet overlooked complications of type 2 diabetes mellitus (T2DM). Individuals with T2DM with CAN have a 5-fold higher rate of cardiovascular morbidity and mortality. The presence of CAN in T2DM could potentially lead to arterial stiffness. However, only sparse data are available suggesting any association between autonomic dysfunction and arterial stiffness in T2DM. MethodsWe recruited 80 people with T2DM and 74 healthy controls for our study. Heart rate variability (HRV) testing was performed to assess autonomic function. Assessment of arterial stiffness was done by measuring the brachial pulse wave velocity (baPWV) and augmentation index (AI). ResultsThe time-domain parameters were significantly decreased (p<0.001) and frequency-domain parameters, such as total power and high-frequency band expressed as a normalized unit, were found to be significantly reduced in people with T2DM (p<0.001). Both baPWV and AI were significantly higher in people with T2DM compared with healthy controls (p<0.001). We observed a moderate correlation between standard deviation of normal to normal interval (SDNN) and baPWV (r=−0.437, p=0.002) and AI (r=−0.403, p=0.002). A multiple linear regression model showed an association between SDNN and arterial stiffness parameters, such as baPWV and AI, which were statistically significant (p<0.05) in a fully adjusted model that included the conventional risk factors for atherosclerosis. ConclusionsImpaired cardiovagal activity is an independent risk factor for the development of arterial stiffness. Incorporation of HRV testing into the diabetes management protocol would have potential benefits for identifying individuals at high risk of developing cardiovascular events. Hence, preventive measures can be taken as early as possible to improve patient outcomes.