Changes In Heart Rate Variability Research Articles

Screening of Cardiac Rhythm Disorders in Women Working at Information Technology Sector Using Continuous Ambulatory Wireless Cardiac Monitoring – A Community-Based Study

Objectives: The role of screening cardiac arrhythmias provides continuum of care to rediscover the causes and prevention strategies. This study was taken up to screen women working in the information and technology sector for cardiac rhythm disorders using continuous ambulatory cardiac monitoring and asses various risk factors along with work-related stress. Materials and Methods: A cross-sectional study was taken up at the workplace to screen women for cardiac rhythm disorders using wireless continuous ambulatory cardiac monitoring. Various risk factors and work-related stress were assessed using a standardized questionnaire. Differences in ECG parameters such as heart rate, heart rate variability (HRV), and frequency corrected QT (QTc) were compared on working and non-working days. Results: A total of 109 women were screened to find a proportion of 4.58% having cardiac arrhythmias. We found two cases of second-degree AV block (type 1), two cases of atrial tachycardia in the age group of 21–30 years, and one case of sinus pauses. Risk factors such as alcohol usage were statistically associated with cardiac arrhythmias. Others included a sedentary lifestyle, being underweight, a lesser number of sleep hours, no physical activity, work-related stress, and the presence of past-COVID-19 infection, but these were not statistically significant. There were significant changes in heart rate, HRV, and QTc prolongation on working day compared to non-working days. Among the domains of work-related stress, the influence at work and perceived stress due to individual demands and commitments contributed the highest mean score. Moreover, those with higher work-related stress scores were at 3.66 times the increased risk of QTc prolongation. Conclusion: The present study implies the combination of the need for the screening tool in younger age groups and lifestyle factors with more elucidation of work-related stress on autonomic cardiac function.

The effect of exercise using incentive spirometry on heart rate variability in patients after COVID-19 infection

Background: COVID-19 infection causes various sequelae and complications after recovery. Changes in heart rate variability (HRV) were found in patients with COVID-19 infection, suggesting a disturbance in the autonomic system. Breathing exercises with diaphragmatic breathing and incentive spirometry have been shown to increase HRV by increasing lung capacity, respiratory muscle strength, and pulmonary O2 pressure, which can affect baroreflex signals. Incentive spirometry is one of the easy-to-use, safe, inexpensive pulmonary rehabilitation exercises that can be done at home without supervision and are accompanied by a visual display as a guide to the patient. The purpose of the study was to determine the effect of giving breathing exercises using Incentive Spirometry for four weeks on Heart Rate Variability in patients post COVID-19 infection Method: This research is an experimental study with a pre-post-test control group design. The treatment group was given breathing exercises using Incentive Spirometry, while the control group used diaphragmatic breathing five times a day, seven times per week, for four weeks in each group. HRV measurement was performed before and after four weeks of intervention, using the parameter Root Mean Square of Successive Differences between normal heartbeats (RMSSD), Standard Deviation of N-N intervals (SDNN), and LF/HF ratio of Heart Rate Variability (HRV). Result: There subject of this study was 20 post-COVID-19 patients divided into a treatment group (n=10) and a control group (n=10). There was no significant increase in RMSSD, SDNN, and LF/HF ratio pre and post-intervention in both groups, suggesting no significant increase in HRV. Conclusion: Exercise with Incentive Spirometry and Diaphragmatic Breathing for four weeks did not increase the Heart Rate Variability value in post-COVID-19 patients.

Changes in Heart Rate Variability with Induction of Gastric Ulcers in Adult Horses.

Gastric ulceration can be induced by athletic training and is a significant welfare concern. The objective of this study was to evaluate the effect of gastric ulcer induction on heart rate variability (HRV) in the horse. We hypothesized that induction of gastric ulcers would decrease HRV and increase low frequency fluctuations, consistent with increased sympathetic tone. A convenience sample of 8 horses in a larger study were enrolled. Horses were randomly assigned to receive water or 2 mg/kg omeprazole orally once daily for 28 days. Gastric ulcers were induced through intermittent feed withholding on days 21 to 28. Gastroscopy was performed and gastric ulcers were graded (0-IV) by three blinded reviewers on days 21 and 28. Continuous electrocardiograms were obtained for one hour at the start and end of ulcer induction. HRV was assessed in 1-hour recordings for time domain variables and 5 minute sections for frequency domain analysis. HRV and ulcer grade across treatments were compared by a mixed effect model, with treatment and time as fixed effects and horse as a random effect. Gastric ulcer grade increased with induction protocol (P < .0001) and decreased with omeprazole treatment (P=.0007). Omeprazole treatment increased R-R intervals (P=.01) and decreased ratio of low frequency/high frequency signal (P=.008) as compared to horses receiving water. This was attributable to decreasing low frequency fluctuations (P=.05). While limited by the small sample size (four horses/treatment), this study suggests that omeprazole treatment decreases heart rate, and LF/HF ratio during ulcer induction, consistent with a decrease in sympathetic tone.

Psychological skills training impacts autonomic nervous system responses to stress during sport-specific imagery: An exploratory study in junior elite shooters.

This study investigated the effects of psychological skills training (PST) in shooters psychophysiologically using heart rate variability (HRV) in addition to psychological questionnaires and participant interviews. Five junior pistol shooters participated in an 8-week PST program consisting of a group session per week followed by individual counseling. Before and after PST, we collected electrocardiography data during rest, mental imagery of sport-related crisis situations, and successful performance, to analyze differences in HRV indices. Participants also responded to the Psychological Skills Inventory for Archery and Shooting (PSIAS), Intrinsic Motivation Inventory (IMI), Sports Anxiety Scale (SAS), and Trait Sport Confidence Inventory (TSCI). Results showed that the perceived competence (pre: 2.52 ± 0.95, post: 3.36 ± 0.73, p = 0.049) and trait sport confidence (pre: 4.94 ± 1.17, post: 6.60 ± 0.65, p = 0.049) significantly improved after PST. The analysis of HRV indicated that the ratio of low-frequency power to high-frequency power (LF/HF ratio) decreased significantly during imagery of crisis (pre: 3.4 ± 2.3, post: 1.014 ± 0.71, p = 0.038) and success (pre: 1.933 ± 0.917, post: 0.988 ± 0.572, p = 0.046), reflecting a strengthened autonomic nervous system's responsiveness to stress. Our findings illustrate that PST can help athletes better cope with psychologically disturbed situations during competition, by providing psychophysiological evidence through HRV changes.

A Systematic Review of Heart Rate Variability as a Measure of Stress in Medical Professionals.

Understanding the physiological effects of responding to crises is a critical component in understanding how to manage and prepare medical professionals to be crisis responders. Heart rate variability (HRV) is the variation in rate between a succession of R-R intervals. This variation is not only affected by physiological processes such as respiration or metabolic rate but is also directly controlledby the autonomic nervous system. As such, heart rate variability has been proposed as a noninvasive tool to measure the physiological stress response. The aim of this systematic review is to consolidate heart rate variability literature in the context of medical emergencies to determine if heart rate variability changes predictably from baseline when responding to medical crises. This may demonstrate utility as an objective, noninvasive measure of stress response. A systematic literature review of six databases yielded 413 articles, 17 of which met our inclusion criteria of being written in English, measuring HRV in healthcare providers, and measuring HRV in real or simulated medical resuscitations or procedures. Articles were then analyzed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) scoring system. Out of the 17 articles reviewed, 11 demonstrated statistically significant results showing heart rate variability responding in a predictable manner to stress. Three articles utilized a medical simulation as the stressor, six used medical procedures, and eight used medical emergencies encountered during clinical work. Overall, a predictable trend in heart rate variability metrics of standard deviation from the mean value of normal-to-normal(N-N) intervals (SDNN), root mean square of the successive differences (RMSSD),mean number of times per time interval in which the change in successive normal sinus (N-N) intervals exceeds 50 ms (PNN50), low frequency % (LF%), and low-frequency-to-high-frequency ratio (LF/HF) was observed when responding to stress. This systematic literature review showed that heart rate variability among healthcare providers responding to stressful scenarios follows a predictable pattern of change and expands our understanding of the physiology of stress in healthcare providers. This review supports the use of HRV to monitor stress during high-fidelity simulation to ensure that appropriate physiological arousal is achieved during the training of medical personnel.

PHYSIOLOGICAL METRICS COLLECTED FROM WEARABLE DEVICES IDENTIFY INFLAMMATORY AND CLINICAL INFLAMMATORY BOWEL DISEASE FLARES

Abstract BACKGROUND Inflammatory bowel disease (IBD) flares are common and unpredictable. Disease monitoring relies on symptom reporting or single timepoint assessments of stool, blood, imaging, or endoscopy—these are inconvenient and invasive and do not always reflect the patient perspective. Advances in wearable technology allow for passive, continuous and non-invasive assessment of physiological metrics including heart rate variability (HRV), the measure of small time differences between each heartbeat, a marker of autonomic nervous system function. Our group has previously demonstrated that changes in autonomic function precedes an IBD flare, can predict psychological state transitions and even identify inflammatory events including SARS-CoV-2 infection. To develop algorithms that can predict IBD flares using wearable device signatures, we launched a national wearable device study called The IBD Forecast study. To assess data quality and feasibility, the first 125 Apple Watch users to enroll were evaluated. METHODS The IBD Forecast study is a prospective cohort study enrolling anyone ≥18 years of age in the United States (US) with IBD who is willing to (1) use a commercially available wearable device, (2) download our custom eHive app and (3) answer daily survey questions. HRV metrics (mean of the standard deviations of all the NN intervals [SDNN]) were analyzed using a mixed-effect cosigner model that incorporated body mass index, age, and sex. SDNN is a time domain HRV index that reflects both sympathetic and parasympathetic nervous system activity and is calculated from the variance of intervals between adjacent QRS complexes (the normal-to-normal [NN] intervals). Clinical flare was assessed with daily Patient Reported Outcome (PRO)-2 surveys (flare; PRO-2 Crohn’s disease &amp;gt;7, PRO-2 ulcerative colitis &amp;gt;2). Inflammatory flare was assessed via patient reported C-reactive protein (CRP), with inflammatory flare defined as &amp;gt;5 mg/L. RESULTS The first 125 study participants were enrolled across 29 states in the US (Table 1). Circadian features of changes of HRV were modelled (Figure 1). The mesor, or midline of the circadian pattern of the SDNN was higher in those with clinical flare (mean 44.43; 95% CI 41.25-47.75) compared to those in clinical remission (mean 43.03; 95% CI 39.94-46.22) (p&amp;lt;0.004). The mesor of the circadian pattern of the SDNN was lower in those with an inflammatory flare (mean 38.16; 95% CI 30.86-45.72) compared to those with normal inflammatory markers (mean 49.51; 95% CI 43.12-56.26) (p&amp;lt;0.001). CONCLUSIONS Longitudinally collected HRV metrics from a commonly worn commercial wearable device can identify symptomatic and inflammatory flares. This preliminary analysis of a small proportion of the IBD Forecast Study cohort demonstrates the feasibility of using wearable devices to identify, and may potentially predict, IBD flares.

Change in heart rate variability during two firefighting work cycles

This study aimed to determine whether the change in heart rate variability from pre to post firefighting is modulated by different work cycles. Thirteen male firefighters underwent two firefighting simulations that comprised two identical 25-min work bouts intercalated by a passive recovery period of either 20 min (T20) or 5 min (T5). The square root of the mean squared differences of successive R–R intervals (RMSSD) and aural temperature were measured at rest before (PRE) and after (POST) firefighting simulations. The decrease in RMSSD was different between firefighting simulations (T20: −10 ± 21.2 ms, T5: −19.9 ± 20.9 ms, interaction, p = 0.02). Post-firefighting aural temperature was greater (p = 0.05) in T5 (37.18 ± 0.53 °C) than in T20 (36.88 ± 0.49 °C). In conclusion, a shorter recovery period of 5 min between firefighting work bouts decreases post-firefighting heart rate variability, possibly attributed to a lower parasympathetic reactivation and a higher absolute value of body temperature.

Tefillin use induces preconditioning associated changes in heart rate variability.

Short bouts of occlusion of blood flow can induce a preconditioning response that reduces subsequent damage from longer periods of ischemia. It has been shown that ischemic preconditioning (IPC) can be elicited remotely (RIPC) through limitation of blood flow and as recently described via only pain sensation. Non-obstructive banding (NOB) through the donning of tefillin (a box with sacred texts attached to a leather strap that is traditionally bound to the non-dominant arm of Jewish adults during morning prayers) has been shown to elicit an RIPC response at least partially through pain sensation. This study evaluated the effects of NOB on heart rate variability (HRV) dependent factors that are known to be affected by various RIPC stimuli. We recruited 30 healthy subjects and subjected them to NOB versus control and found various HRV markers associated with RIPC to be changed in the NOB group. This finding provides further evidence that tefillin, likely through NOB induced RIPC changes, may still be a viable clinical pathway to prevent and decrease the morbidity associated with ischemic events.

Heart rate variability and microvolt Twave alternans changes during ajmaline test may predict prognosis in Brugada syndrome.

Drug-induced typeI Brugada syndrome (BrS) is associated with a ventricular arrhythmia (VA) rate of 1 case per 100 person-years. This study aims to evaluate changes in electrocardiographic (ECG) parameters such as microvolt Twave alternans (mTWA) and heart rate variability (HRV) at baseline and during ajmaline testing for BrS diagnosis. Consecutive patients diagnosed with BrS during ajmaline testing with 5-year follow-up were included in this study. For comparison, a negative ajmaline control group and an isoproterenol control group were also included. ECG recordings during ajmaline or isoproterenol test were divided in two timeframes from which ECG parameters were calculated: a 5-min baseline timeframe and a 5-min drug timeframe. A total of 308 patients with BrS were included, 22 (0.7%) of which suffered VAs during follow-up. One hundred patients were included in both isoproterenol and negative ajmaline control groups. At baseline, there was no difference in ECG parameters between control groups and patients with BrS, nor between BrS with and without VAs. During ajmaline testing, BrS with VAs presented longer QRS duration [159 ± 34ms versus 138 (122-155) ms, p = 0.006], higher maximum mTWA [33.8 (14.0-114) µV versus 8.00 (3.67-28.2)µV, p = 0.001], and lower power in low frequency band [25.6 (5.8-53.8) ms2 versus 129.5 (52.7-286) ms2, p < 0.0001] when compared to BrS without VAs. Ajmaline induced important HRV changes similar to those observed during isoproterenol. Increased mTWA was observed only in patients with BrS. BrS with VAs during follow-up presented worse changes during ajmaline test, including lower LF power and higher maximum mTWA which were independent predictors of events.

Changes in Maternal Heart Rate and Autonomic Regulation following the Antenatal Administration of Corticosteroids: A Secondary Analysis.

While the effect of antenatally administered corticosteroids on fetal heart rate (HR) and heart rate variability (HRV) is well established, little information is available on how these drugs affect maternal physiology. In this secondary analysis of a prospective, observational cohort study, we quantify how corticosteroids affect maternal HR and HRV, which serve as a proxy measure for autonomic regulation. Abdominal ECG measurements were recorded before and in the five days following the administration of betamethasone-a corticosteroid commonly used for fetal maturation-in 46 women with singleton pregnancies. Maternal HR and HRV were determined from these recordings and compared between these days. HRV was assessed with time- and frequency-domain features, as well as non-linear and complexity features. In the 24 h after betamethasone administration, maternal HR was significantly increased (p &lt; 0.01) by approximately 10 beats per minute, while HRV features linked to parasympathetic activity and HR complexity were significantly decreased (p &lt; 0.01 and p &lt; 0.001, respectively). Within four days after the initial administration of betamethasone, HR decreases and HRV features increase again, indicating a diminishing effect of betamethasone a few days after administration. We conclude that betamethasone administration results in changes in maternal HR and HRV, despite the heterogeneity of the studied population. Therefore, its recent administration should be considered when evaluating these cardiovascular metrics.

Effects of High-Intensity Interval Training and Continuous Training on Exercise Capacity, Heart Rate Variability and Isolated Hearts in Diabetic Rats.

High-intensity interval training (HIIT) has been suggested as an alternative for continuous training (CT) in people with diabetes mellitus (DM) due to its short duration and potential to improve adherence to exercise. However, data on its impact on heart rate variability (HRV) are scarce. To assess and compare the effects of HIIT and CT on exercise capacity, HRV and isolated hearts in diabetic rats. DM (intravenous streptozotocin, 45 mg.kg -1 ) and control (C) animals performed 20 sessions (5 days/week, 50 min, for 4 weeks) of CT on a treadmill (70% of maximal exercise capacity) or HIIT (cycles of 1:1min at 50% and 90% of maximal exercise capacity). HRV was assessed by continuous electrocardiogram, and cardiac function assessed in isolated perfused hearts. For data analysis, we used the framework of the multivariate covariance generalized linear model or one-way ANOVA followed by Tukey's test, considering p<0.05 as significant. Higher exercise capacity (m/min) was achieved in HIIT (DM-HIIT: 36.5 [IQR 30.0-41.3]; C-HIIT: 41.5 [37.8-44.5], both n=10) compared to CT (DM-CT: 29.0 [23.8-33.0]; C-CT: 32.0 [29.5-37.0], both n=10) (p<0.001). Heart rate (bpm) was lower in DM compared to controls (p<0.001) both in vivo (DM-HIIT:348±51, C-HIIT:441±66, DM-CT:361±70, C-CT:437±38) and in isolated hearts. There were no differences in HRV between the groups. Maximum and minimal dP/dt were reduced in DM, except +dP/dt in DM-HIIT vs. C-HIIT (mean difference: 595.5±250.3, p=0.190). Short-term HIIT promotes greater improvement in exercise performance compared to CT, including in DM, without causing significant changes in HRV.

Body fat and muscle in relation to heart rate variability in young-to-middle age men: a cross sectional study

Background While obesity is recognisably associated with changes in heart rate variability (HRV), the association between skeletal muscle mass and HRV is less clear. Aims In this cross sectional study, we analysed the association of body fat (four parameters) and muscle mass (five parameters) with indicators of HRV activity. Subjects and methods Assessment of body composition and HRV was performed in n = 180 young-to-middle age healthy men exposed to high occupational physical activity, using the multi-frequency bioelectrical impedance device and the PPG-StressFlow® HRV photoplethysmography device, respectively. Results Mean values of parameters of fat tissue were above normal/reference values. Muscle tissue indicators were higher or within the reference ranges. Fat tissue parameters were significantly higher in participants with lower parasympathetic nervous system (PNS) indicators. Weight-adjusted skeletal muscle index (wSMI) was significantly lower in men with reduced PNS parameters. Fat tissue parameters were negatively correlated with PNS parameters, while wSMI was positively correlated with PNS parameters. Conclusions Participants with higher fat mass and lower muscle mass had poorer parasympathetic activity. Since mean values of HRV parameters indicated mild parasympathetic dominance, we conclude that physical activity and consequently good muscle mass potentially compensated for the negative interaction between fat tissue and HRV.

Reduced Heartbeat-Evoked Responses in a Near-Death Case Report.

Whether brain-heart communication continues under ventricular fibrillation (VF) remains to be determined. There is weak evidence of physiological changes in cortical activity under VF. Moreover, brain-heart communication has not previously been studied in this condition. We aimed to measure parallel changes in heart-rate variability (HRV), cortical activity, and brain-heart interactions in a patient who experienced VF. The EEG and EKG signals for the case report were acquired for approximately 20 h. We selected different 1-min-long segments based on the changes in the EKG waveform. We present the changes in heartbeat-evoked responses (HERs), HRV, and EEG power for each selected segment. The overall physiological activity appeared to deteriorate as VF proceeded. Brain-heart interactions measured using HERs disappeared, with a few aberrant amplitudes appearing occasionally. The parallel changes in EEG and HRV were not pronounced, suggesting the absence of bidirectional neural control. Our measurements of brain-heart interactions suggested that the evolving VF impairs communication between the central and autonomic nervous systems. These results may support that reduced brain-heart interactions reflect loss of consciousness and deterioration in the overall health state.

Heart Rate Variability among Healthy Untrained Adults during Mild Intensity Stationary Cycling Exercise.

Stationary cycling is the popular, preferred, and convenient form of exercise. During exercise, autonomic modulation is seen which can be assessed by heart rate variability (HRV). The aim of the study was to evaluate the changes in HRV during mild-intensity cycling exercise. An observational cross-sectional study was done on 20 healthy male volunteers with the age (35.44 ± 4.12), height (71.12 ± 11.98), and weight (161.23 ± 11.65), BMI (27.12 ± 3.49) attending various YOGA sessions in AYUSH OPD. Volunteers underwent an exercise program at the mild intensity of 30% to 50% of maximal heart rate on a stationary cycle for 20 min. HRV was recorded by the HRV mobile unit Dynamika Machine at rest, every 5 min (4×) over 20 min and during the recovery period. Repeated measures of analysis of variance with post-hoc analysis with Bonferroni and Holm's multiple comparisons. Significant change was observed in mean heart rate and time domain parameters. Frequency domain parameters that showed significant change were total power, High Frequency- HF (ms2), Very Low Frequency -VLF (ms2), Low Frequency -LF (ms2), and Very Low Frequency %-VLF (%). The HRV parameters conclusively point towards cardiac parasympathetic withdrawal and sympathetic dominance at the initiation of exercise. With the progression of exercise, the sympathetic influence is retained. In the recovery period parasympathetic reactivation gains control over heart rate as well as HRV. The HRV response to exercise challenges may be helpful in designing exercise programs based on variations in the autonomic response.

Correlation between heart rate variability and cerebral autoregulation in septic patients.

Heart rate variability (HRV) may provide an estimation of the autonomous nervous system (ANS) integrity in critically ill patients. Disturbances of cerebral autoregulation (CAR) may share common pathways of ANS dysfunction. To explore whether changes in HRV and CAR index correlate in critically ill septic patients. Prospectively collected data on septic adult (> 18years) patients admitted into a mixed Intensive Care between February 2016 and August 2019 with a recorded transcranial doppler CAR assessment. CAR was assessed calculating the Pearson's correlation coefficient (i.e. mean flow index, Mxa) between the left middle cerebral artery flow velocity (FV), insonated with a 2-MHz probe, and invasive blood pressure (BP) signal, both recorded simultaneously through a Doppler Box (DWL, Germany). MATLAB software was used for CAR assessment using a validated script; a Mxa >0.3 was considered as impaired CAR. HRV was assessed during the same time period using a specific software (Kubios HRV 3.2.0) and analyzed in both time-domain and frequency domain methods. Correlation between HRV-derived variables and Mxa were assessed using the Spearman's coefficient. A total of 141 septic patients was studied; median Mxa was 0.35 [0.13-0.60], with 77 (54.6%) patients having an impaired CAR. Mxa had a significant although weak correlation with HRV time domain (SDNN, r=0.17, p=0.04; RMSSD, r=0.18, p=0.03; NN50, r=0.23, p=0.006; pNN50, r=0.23, p=0.007), frequency domain (FFT-HF, r=0.21; p=0.01; AR-HF, r=0.19; p=0.02), and non-linear domain (SD1, r=0.18, p=0.03) parameters. Impaired CAR patients had also all of these HRV-derived parameters higher than those with intact CAR. In this exploratory study, a potential association of ANS dysfunction and impaired CAR during sepsis was observed.

A Study to Assess Changes in Cortisol Level and Heart Rate Variability between Fixed Duty and Shift Duty Health Care Providers in a Tertiary Care HospitalA Cross-Sectional Study

Introduction: Increased demand of service 24 hours around the clock has divided the workers into 2 domains as “Fixed duty” and “Shift duty”. Personals associated with shift duty are increasing in numbers day by day. Shift duty or more specifically night duty is associated with increased stress which results in high morbidity and decrease in work efficiency. Cortisol hormone and Heart Rate Variability (HRV) are useful parameters to determine the effects of stress. Aim: To find any change in cortisol levels, HRV, Athens score among the fixed duty and shift duty healthcare providers. Materials and Methods: A descriptive cross-sectional comparative study was conducted in a tertiary care hospital at Kolkata between July, 15th to Sept, 15th 2021. Predesigned and pretested questionnaire was made and ethical clearance was taken from institutional IEC. Then after taking consent total 120 (60 fixed duty and 60 shift duty) healthcare providers were recruited for the study. Subjects of the study filled up a questionnaire {including Athens Insomnia Scale (AIS)}. After applying exclusion criteria (any cardiovascular, neurological, psychological, sleep disorder) 120 health individuals were taken five minutes short-term HRV (time and frequency domain) recording in supine posture and 4 PM blood sample (for cortisol) were obtained from the participants which was further analysed in Chemiluminescence Immunoassay (CLI). Data was analysed in SPSS version 20.0. Statistical tests like student t-test, Cron bach’s alpha and chi-square tests were applied significant p&lt;0.05 (95% CI). Results: After analysis, shift duty workers showed a significant (p&lt;0.001, Odd’s 10.706) higher chance of having insomnia (Athens score &gt;6) than fixed duty workers. Blood test showed that shift duty workers had significantly high evening cortisol level than fixed duty workers (p= 0.036). The time domain of HRV showed that the parameters like Standard Deviation all NN interval (SDNN) (p=0.001), Mean HR (p=0.037), RMSSD (p &lt;0.001), NN50 (p=0.006), pNN50 (p=0.002) were significantly different in the two groups. Whereas the frequency domain of HRV showed that HF power was lower and LF power (p=0.002), LF/HF ratio (p &lt;0.001) were significantly higher in shift duty workers. Conclusion: The study showed that shift duty workers had comparatively higher stress levels resulting in significantly high sympathetic drive and increased risk of insomnia. This can be associated with morbidity and ill health in the shifting duty workers.

Cardioneuroablation for Reflex Syncope: Efficacy and Effects on Autonomic Cardiac Regulation-AProspective Randomized Trial.

Treatment of cardioinhibitory vasovagal syncope (VVS) is difficult. Recently, cardioneuroablation (CNA) has emerged as a new therapeutic option. This study sought to assess the effects of CNA on syncope recurrences in patients with VVS. This study was a prospective, open, randomized, controlled, investigator-initiated trial comparing CNA versus optimal nonpharmacologic therapy in patients with cardioinhibitory VVS. Patients were included if they had documented symptomatic cardioinhibitory or mixed VVS and positive atropine test. CNA was performed using radiofrequency ablation of the ganglionated plexi from the left and right atria. Follow-up lasted 2 years. Primary endpoint was time to first syncope recurrence. Secondary endpoints included changes in sinus rhythm and heart ratevariability measured in Holter electrocardiography at baseline and 3, 12, and 24months after CNA, as well as changesin quality of life at baseline and after completion of follow-up. A total of 48 patients (17 male, mean age 38 ± 10 years, 24 in CNA group, 24 in control group) entered thestudy. The primary endpoint occurred in 2 patients (8%) from the CNA group versus 13 control patients (54%) (P=0.0004). After CNA the mean sinus rhythm at 24-hour Holter electrocardiography was significantly faster and heart rate variability parameters significantly changed toward parasympathetic withdrawal compared with baseline values. Quality of life significantly improved in the CNA group (30 ± 10 points vs 10 ± 7 points; P = 0.0001), whereas it remained stable in control patients (31 ± 10 points vs 30 ± 10 points; P = 0.5501). This is the first randomized study documenting efficacy of CNA in patients with cardioinhibitory VVS. Larger studies are needed to confirm these findings. (Cardioneuroablation for Reflex Syncope [ROMAN]; NCT03903744).

Association between the severity of nocturnal asymptomatic hypoglycemia and heart rate variability change in patients with type 2 diabetes

Association between the severity of nocturnal asymptomatic hypoglycemia and heart rate variability change in patients with type 2 diabetes

Wearable-Measured Sleep and Resting Heart Rate Variability as an Outcome of and Predictor for Subjective Stress Measures: A Multiple N-of-1 Observational Study.

The effects of stress may be alleviated when its impact or a decreased stress-resilience are detected early. This study explores whether wearable-measured sleep and resting HRV in police officers can be predicted by stress-related Ecological Momentary Assessment (EMA) measures in preceding days and predict stress-related EMA outcomes in subsequent days. Eight police officers used an Oura ring to collect daily Total Sleep Time (TST) and resting Heart Rate Variability (HRV) and an EMA app for measuring demands, stress, mental exhaustion, and vigor during 15-55 weeks. Vector Autoregression (VAR) models were created and complemented by Granger causation tests and Impulse Response Function visualizations. Demands negatively predicted TST and HRV in one participant. TST negatively predicted demands, stress, and mental exhaustion in two, three, and five participants, respectively, and positively predicted vigor in five participants. HRV negatively predicted demands in two participants, and stress and mental exhaustion in one participant. Changes in HRV lasted longer than those in TST. Bidirectional associations of TST and resting HRV with stress-related outcomes were observed at a weak-to-moderate strength, but not consistently across participants. TST and resting HRV are more consistent predictors of stress-resilience in upcoming days than indicators of stress-related measures in prior days.

Improved arterial stiffness after combined aerobic and resistance training: correlation with heart rate variability change in prehypertensive offspring of hypertensive parents.

Prehypertensive offspring of hypertensive parents are strongly linked to pathological processes of hypertension in later life. It is observed that young adults with high blood pressure (BP) have increased arterial stiffness, which is linked to autonomic anomalies. The purpose of the present study was to assess the effect of combined resistance and aerobic exercise training on BP, brachial-ankle pulse wave velocity (baP-WV), and heart rate variability (HRV) in prehypertensive young men with hypertensive parents. Thirty prehypertensive males aged 19.6±1.2 years were randomly assigned to either a combined exercise training group (CBT, n=15) or no exercise group (CON, n=15). The CBT group performed combined exercise for 8 weeks, 3 times per week. BP, baP-WV, HRV, peak oxygen consumption (VO2peak), and muscle strength were measured before and after the exercise intervention. Systolic BP (-5.1 mmHg, 3.9% decrease, P<0.05), diastolic BP (-3.9 mmHg, 6.1% decrease, P<0.01), mean arterial pressure (-4.2 mmHg, 4.7% decrease, P<0.05), baPWV (-0.4 m/sec, 3.5% decrease, P<0.01), standard deviation of all RR intervals (+58.5% increase, P<0.05) and very low frequency (VLF) (+34.6% increase, P<0.01), VO2peak (+11.7% increase, P<0.01) and one-repetition maximum leg press (+30.3% increase, P<0.01) were significantly improved in the CBT group after 8 weeks of training versus the CON group. Additionally, a reduction in baPWV was associated with an increase in the VLF power of HRV (r=0.72, P<0.01). These findings indicate that the combined training improves BP, arterial stiffness, vagal activity, cardiorespiratory fitness, and lower-body muscle strength in prehypertensive offspring of hypertensive parents.