Standard Deviation Of NN Intervals Research Articles

Heart and Breathing Rate Variations as Biomarkers for Anxiety Detection.

With advances in portable and wearable devices, it should be possible to analyze and interpret the collected biosignals from those devices to tailor a psychological intervention to help patients. This study focuses on detecting anxiety by using a portable device that collects electrocardiogram (ECG) and respiration (RSP) signals. The feature extraction focused on heart-rate variability (HRV) and breathing-rate variability (BRV). We show that a significant change in these signals occurred between the non-anxiety-induced and anxiety-induced states. The HRV biomarkers were the mean heart rate (MHR; p¯ = 0.04), the standard deviation of the heart rate (SD; p¯ = 0.01), and the standard deviation of NN intervals (SDNN; p¯ = 0.03) for ECG signals, and the mean breath rate (MBR; p¯ = 0.002), the standard deviation of the breath rate (SD; p¯ < 0.0001), the root mean square of successive differences (RMSSD; p¯ < 0.0001) and SDNN (p¯ < 0.0001) for RSP signals. This work extends the existing literature on the relationship between stress and HRV/BRV by being the first to introduce a transitional phase. It contributes to systematically processing mental and emotional impulse data in humans measured via ECG and RSP signals. On the basis of these identified biomarkers, artificial-intelligence or machine-learning algorithms, and rule-based classification, the automated biosignal-based psychological assessment of patients could be within reach. This creates a broad basis for detecting and evaluating psychological abnormalities in individuals upon which future psychological treatment methods could be built using portable and wearable devices.

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

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

Parasympathetic Versus Sympathetic Changes in Heart Rate Variability After a Multimodal Integrative Medicine Intervention for Frontline COVID-19 Personnel.

Frontline healthcare providers (HCPs) working in COVID-19 hospital departments need to deal with considerable physical and emotional stress on a daily basis. We conducted a pilot study to examine changes in heart rate variability (HRV) in frontline COVID-19 personnel after an integrative medicine (IM) intervention. HCPs working in isolated COVID-19 inpatient departments underwent a single 30-minute individually tailored IM sessions combining various IM modalities (acupuncture, mind-body, and/or manual-movement modalities, including anthroposophic medicine). HRV parameters were compared during the first IM session at 3-minute intervals, at the beginning of treatments, and after 20 minutes. Root mean square of successive RR interval differences (RMSSD) was measured, as were domains of time (standard deviation of NN intervals, percentage of successive RR intervals that differ by more than 50 milliseconds) and frequency (low frequency/high frequency [LF/HF] ratio). Preintervention and postintervention concerns were assessed using the Measure Yourself Concerns and Well-being questionnaire, with posttreatment free-text narratives analyzed for clusters of emotional- and spiritual-related keywords (ESKs). A total of 114 HCPs underwent an IM treatment session, and their HRV values were measured, of which 75 (65.8%) expressed ESKs. The RMSSD increased only in the ESK-expressing group ( p < .001). LF/HF ratios decreased in both groups, with HF power increasing in the ESK-expressing ( p = .043) and LF power decreasing in the non-ESK-expressing groups ( p = .004). Increased parasympathetic activity was observed in all HCPs after the IM intervention, particularly among those expressing ESKs. LF/HF parameters suggest different relaxation-associated mechanisms, with increased HF (regulated predominantly by parasympathetic tone) in the ESK-expressing and decreased LF (regulated partially by sympathetic tone) in the nonexpressing group. Additional research needs to explore the relationship between subjective effects of the IM intervention and physiological mechanisms of relaxation in HCPs working in stressful environments. ClinicalTrials.gov identifier NCT05104827.

Abstract 13303: Influence of ARNI on Cardiac Autonomic Nervous System

Background Mortality in heart failure with reduced ejection fraction (HFrEF) is associated with imbalance of cardiac autonomic nervous system (CANS). Sacubitril/ Valsartan (ARNI) reduces risk of death and HFrEF hospitalization. Whether ARNI exerts effects on CANS has not been studied. Accordingly, we prospectively compared heart rate variability (HRV) as a noninvasive measure of CANS before and after initiation of ARNI therapy. Methods: The study was as a single-arm prospective interventional study. Patients with HFrEF underwent echocardiography and standardized 30-minute 12-lead Holter ECG recording before and 3 months after initiation of ARNI therapy. Study endpoints were changes in HRV parameters (standard deviation of normal-to-normal intervals (SDNN), mean square of differences between consecutive R-R intervals (RMSSD), periodic repolarization dynamics (PRD) and deceleration capacity (DC) as well as left ventricular ejection fraction (LVEF) and heart rate (HR). Results: Between June 2021 and March 2022 we recruited 63 consecutive patients. At follow-up 48 (76.2%) patients were still on ARNI and therefore analyzed. Mean age was 65±13 years, 88% were male. All patients received identical beta-blockers dosage at baseline and follow-up. Heart rate was reduced by ~12% (P=0.005). SDNN increased by ~42% (P&lt;0.001), RMSSD by ~55% (P&lt;0.001) and ~DC by 370% (P&lt;0.001). No change in PRD was observed (P=0.13). These results were accompanied by increased LVEF (28±6% vs. 38±10%, P&lt;0.001) and reduced plasma nt-proBNP levels (5083±790 pg/ml vs. 1838±621 pg/ml, P=0.002). NYHA class improved from III to II. Conclusion Significant increase of parasympathetic CANS tone was observed after initiation of ARNI therapy as evidenced by decreased HR, increased DC, SDNN and RMSSD. Part of the beneficial effects of ARNI might be related to the accentuation of parasympathetic CANS modulating mortality risk and risk for HFrEF hospitalizations.

Advanced glycation end-products are associated with diabetic neuropathy in young adults with type 1 diabetes.

Aims/hypothesisAdvanced glycation end-products (AGEs) may contribute to the development of diabetic neuropathy. In young adults with type 1 diabetes, we aimed to investigate the association between AGEs and cardiovascular autonomic neuropathy (CAN) and distal symmetric polyneuropathy (DSPN).MethodsThis cross-sectional study comprised 151 young adults. CAN was assessed by cardiovascular autonomic reflex tests; lying-to-standing test, deep breathing test (E/I), Valsalva manoeuvre, and heart rate variability indices; and the mean square of the sum of the squares of differences between consecutive R-R intervals and standard deviation of normal-to-normal intervals (SDNN), high- (HF) and low-frequency (LF) power, total frequency power, and the LF/HF ratio. DSPN was assessed by light touch, pain and vibration perception threshold (VPT), neuropathy questionnaires, and objective measures. AGEs were analysed in four groups using z-scores adjusted for relevant confounders and multiple testing: i) “glycolytic dysfunction”, ii) “lipid peroxidation”, iii) “oxidative stress”, and iv) “glucotoxicity”.ResultsA higher z-score of “glycolytic dysfunction” was associated with higher VPT (4.14% (95% CI 1.31; 7.04), p = 0.004) and E/I (0.03% (95% CI 0.01; 0.05), p = 0.005), “lipid peroxidation” was associated with higher LF/HF ratio (37.72% (95% CI 1.12; 87.57), p = 0.044), and “glucotoxicity” was associated with lower SDNN (−4.20% (95% CI −8.1416; −0.0896), p = 0.047). No significance remained after adjustment for multiple testing.Conclusions/interpretationsIn young adults with type 1 diabetes, increased levels of AGEs involving different metabolic pathways were associated with several measures of CAN and DSPN, suggesting that AGEs may play a diverse role in the pathogeneses of diabetic neuropathy.

Prognostic value of heart rate variability in acute coronary syndrome.

To assess the predictive value of pre-discharge heart rate variability (HRV) parameters in patients with acute coronary syndrome (ACS) treated by percutaneous coronary intervention (PCI). 145 consecutive male patients with ACS (aged 57.12±10.81years) were included in this study. Fifteen minutes electrocardiogram recording was done to measure time-domain [standard deviation of N-N intervals (SDNN), root-mean square differences of successive R-R intervals (rMSSD)] and frequency-domain [low-frequency (LF) power, high-frequency (HF) power and total power (TP)] HRV parameters before and after PCI. The primary end point was the occurrence of major clinical events (MCE) defined as death, sudden death or re-acute myocardial infarction at the end of 3months follow-up. At a follow-up of 3months, MCE occurred in 06 patients (4.14%) (Cardiac death was 3.01%, while that of sudden death was 1.13%). Out of six-MCE, four deaths and two re-AMIs occurred. Pre-discharge HRV values (SDNN, rMSSD, TP, LF and HF) were significantly lower in patients with ACS without MCE. Only total power HRV index (AUC=0.748; p=0.040) showed greater prognostic accuracy. In conclusion, study showed an increase in SDNN, rMSSD, LF, HF and TP after successful revascularization with PCI in patients who had MCE. The resultant sensitivity, specificity of HRV is still limited in the present study. Particularly, its sensitivity is higher (33-83%) with a modest specificity (61-72%).

ARNI effects in HFrEF. Risk reduction beyond LVEF

Abstract Background The imbalance of cardiac autonomic nervous system function plays an important role in heart failure associated mortality. ARNI has demonstrated a paramount effect in reducing risk of death and hospitalization for worsening of heart failure. However, its exact mechanism of action remains only partly understood. We sought to prospectively compare heart rate variability as a noninvasive measure of cardiac autonomic nervous system function. Methods The study design was prospective sequential observational. Patients served as their own internal control. Patients with heart failure with reduced ejection fraction (HFrEF) receiving optimal medical therapy who were scheduled for a switch to ARNI therapy underwent echocardiography and a standardized 30-minute 12-lead Holter ECG recording before starting ARNI therapy. A monitoring of the parameters was performed 3 months after the start of therapy. Physicians were instructed to increase ARNI dose to the highest tolerated or maximum dose. Besides left ventricular ejection fraction (LVEF) we assessed heart rate (HR), standard deviation of normal-to-normal intervals (SDNN) and mean square of differences between consecutive R-R intervals (RMSSD). Results We recruited 55 patients and baseline characteristics were as follows: age 65±12 years, male sex 78%, NT-proBNP 4989±809 pg/ml, LVEF 28±6%, HR 75±9 bpm, SDNN 43±2 ms, RMSSD 19±2 ms. All patients received beta-blocker therapy and the dosage was similar at baseline and follow-up. After 3 months of ARNI therapy, heart rate showed a significant reduction of 7% (74±14 bpm vs. 69±11 min, P=0.005). SDNN increased by 49% (43±2 ms vs. 64±4 ms, P&amp;lt;0.001) and RMSSD by 42% (19±2 ms vs. 27±3 ms, P=0.01). These results were accompanied by increased LVEF (28±6% vs. 38±10%, P&amp;lt;0.001) and reduced plasma NT-proBNP levels (4989±809 pg/ml vs. 2602±87 pg/ml, P&amp;lt;0.04). NYHA Class of affected patients changed from III to II. Conclusion After changing from ACE/AT1-I to ARNI, significant improvement of autonomic cardiac nervous system function could be observed. ARNI apparently activates the parasympathetic nervous system as suggested by decreased HR and increased SDNN and RMSSD. Therefore, part of its cardioprotective and beneficial effects may relate to the restoration of autonomic cardiac nervous system function. Potential beneficial effects regarding incidence of sudden cardiac arrest may relate to these observations. Funding Acknowledgement Type of funding sources: None.

Time Domain Measures of Heart Rate Variability to Assess Cardiac Autonomic Nerve Function in Adult Bangladeshi Male and Female

Background: Heart rate variability (HRV) has been considered as an indicator of autonomic nerve function status.Objective:To find out the reference values of heart rate variability by time domain measures of HRV inadult Bangladeshi population of both sexes.Methods:This cross-sectional, analytical study was conducted between July 2012 and June 2013. A total of 180 subjects were selected through the Department of Physiology, Dhaka Medical College Dhaka, Bangladesh, with the age ranging from 18 to 60 years. All the study subjects were divided into 3 different groups: group A (18-30 years), group B (31-45 years) and group C (46-60 years). Each group had 60 subjects: 30 males and 30 females. The experimentation of HRV parameters and recording of data were done using RMS Polyrite D (version 2.4) in Autonomic Nerve Function Test Laboratory of the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Mean systolic and diastolic blood pressure, heart rate along with R-R interval between successive QRS complexes, standard deviation of NN interval (SDNN), RMSSD (square root of mean squared differences between adjacent NN intervals) were observed and analyzed.Results: Systolic and diastolic blood pressure and RMSSD were significantly higher in males than that of females in all three groups (P&lt;0.001). However, no differences were observed in mean heart rate, R-R interval, and SDNN between males and females in any group.Conclusion: Our data suggest that males have higher cardiac sympathetic activities, while females show higher cardiac parasympathetic activities in different age groups in terms of heart rate and blood pressure regulation. The difference of blood pressure is statistically significant; however, the difference of mean heart rate is not statistically significant.International Journal of Human and Health Sciences Vol. 06 No. 04 Oct’22 Page: 393-397

Heart rate variability changes in patients with obstructive sleep apnea: A systematic review and meta-analysis.

Obstructive sleep apnea is a common sleep breathing disorder related to autonomic nervous function disturbances. Heart rate variability is an important non-invasive indicator of autonomic nervous system function. The PubMed, Embase, Medline and Web of Science databases were systematically searched for English literature comparing patients with obstructive sleep apnea with controls up to May 2021. Heart rate variability outcomes, including integrated indices (parasympathetic function and total variability), time domain indices (the standard deviation of NN intervals and the root mean square of the successive differences between normal heartbeats) and frequency domain indices (high-frequency, low-frequency, very-low-frequency and the ratio of low-frequency to high-frequency) were derived from the studies. Twenty-two studies that included 2565 patients with obstructive sleep apnea and 1089 healthy controls were included. Compared with controls, patients with obstructive sleep apnea exhibited significantly reduced parasympathetic function. For the obstructive sleep apnea severity subgroup meta-analysis, patients with severe obstructive sleep apnea had significantly lower parasympathetic function, high-frequency, root mean square of the successive differences between normal heartbeats and standard deviation of NN intervals, and higher low-frequency and ratios of low-frequency to high-frequency. However, only the ratio of low-frequency to high-frequency was significantly higher in patients with moderate obstructive sleep apnea than in controls. Finally, for the collection time analysis, patients with obstructive sleep apnea had significantly higher low-frequency and ratio of low-frequency to high-frequency at night, significantly lower parasympathetic function, high-frequency, root mean square of the successive differences between normal heartbeats and standard deviation of NN intervals, and a higher ratio of low-frequency to high-frequency during the day than controls. Autonomic function impairment was more serious in patients with severe obstructive sleep apnea. During sleep, low-frequency can well reflect the impairment of autonomic function in obstructive sleep apnea, and the ratio of low-frequency to high-frequency may play an important role in obstructive sleep apnea diagnosis.

Retrospective analysis of autonomic dysfunction in epilepsy patients from neurophysiological recordings

Autonomic dysfunction is often associated with seizures in patients with epilepsy. Autonomic dysfunction during seizures can cause serious events like cardiac arrest and sudden unexplained death. Early detection of autonomic dysfunction is crucial to avoid such medical emergencies. In our study, we analyzed the heart rate variability (HRV) in physiological recording during the preictal, ictal and postictal periods. A total of 142 seizures with various semiologies recorded from 49 epilepsy patients were included. Time-domain measurements including mean hear rate (HR), RR interval (RRI), root-mean-square of successive R-R interval differences (RMSSD), The standard deviation of N-N intervals (SDNN) and percentage of successive RR intervals that differ by more than 50 ms(pNN50) were analyzed at different time points, 20 minutes before the seizure, 1 minute before the seizure, during the seizure and 20 minutes after the seizure. We observed there was a significant difference in HRV parameters during and just before the seizure onset (RMSSD with p-value&lt;0.001 and SDNN with p-value&lt;0.001). We also observed that there was a suppression of parasympathetic activity and activation of sympathetic stimulation in the ictal and peri-ictal period, which was characterized by an elevation in the mean heart rate (HR), whereas the mean RRI showed an inversely proportional trend. There was a reduction in mean RMSSD, SDNN and pNN50 prior to seizure onset and was more pronounced in generalized seizures as compared to focal seizures with preserved or impaired awareness. There was a greater sympathetic activation and parasympathetic inhibition during an epileptic seizure in females as compared to male patients. These findings suggest that autonomic dysregulation was increased during a generalized seizure when compared to a focal seizure. HRV analysis can be used as a valid method for quantifying central influences on the autonomic nervous system and its cardiac control. A major advantage of electrocardiogram (ECG)-based seizure detection is that the ECG is an essentially easier signal to obtain, with a higher signal-to-noise ratio than EEG (electroencephalogram). Based on the inferences from this study future studies could be done to build machine learning models which could form the base for the development of wearable seizure prediction devices.

PARASYMPATHATIC PREDOMINANCE IS ASSOCIATED WITH POSTEXERCISE HYPOTENSION BEFORE AND AFTER TRAINING AMONG ADULTS WITH HYPERTENSION

Postexercise hypotension (PEH) is the immediate reduction in blood pressure (BP) after an acute exercise persisting for 24 hr. We have suggestive evidence autonomic activity as measured by heart rate variability (HRV) may influence PEH that requires confirmation. PURPOSE:To better establish the relationship between PEH and HRV before and after aerobic training among adults with hypertension. METHODS: Participants completed a moderate to vigorous intensity aerobic training program for 40-50 min/session, 3 d/wk for 12 wk. Before and after training, they performed a peak graded exercise stress test (GEST) and non-exercise control (CONTROL) session leaving the laboratory attached to an ambulatory BP monitor for 19 hr. HRV was measured in the supine position for 5 min using a 12-lead electrocardiogram prior to CONTROL. RESULTS: Participants were middle-aged (52.1 ± 11.7 yr) men (n = 9) and women (n = 9) with hypertension (131.7 ± 9.8 mmHg/85.9 ± 8.5 mmHg) and obesity (body mass index [BMI] 30.0 ± 3.7 kg.m-2). Before training, ambulatory systolic BP (ASBP) decreased 3.2 ± 2.1 mmHg (p = 0.016), and diastolic ABP (ADBP) decreased 2.5 ± 1.5 mmHg (p = 0.015) from baseline during the day following GEST versus CONTROL. After training, ASBP tended to decrease 3.5 ± 2.2 mmHg (p = 0.055), and ADBP decreased 1.7 ± 2.5 mmHg (p < 0.001) from baseline during the day following GEST versus CONTROL. Before training, HRV high frequency (HFms2) (β = 0.441), age (β = -0.568), and resting SBP (β = -0.504) accounted for 66.8% of the variance in ASBP (p < 0.001), whereas the low frequency (LF)/HF ratio (β = -0.516) and resting DBP (β = -0.277) accounted for 35.7% of the variance in ADBP during the day (p = 0.037). After training, the standard deviation of NN intervals (SDNN) (β = 0.556), age (β = -0.506), and resting SBP (β = -0.259) accounted for 60.7% of the variance in ASBP (p = 0.004), whereas SDNN (β = 0.236) and resting DBP (β = -0.785) accounted for 58.5% of the variance in ADBP during the day (p = 0.001). CONCLUSIONS: Adults with hypertension and parasympathetic predominance, as reflected by higher SDNN and HFms2 and lower LF/HF at rest, elicited PEH to a greater extent independent of training status compared to adults with sympathetic predominance. Our results highlight resting autonomic activity is an important determinant of PEH that should be explored further.

Cardiorespiratory function, resting metabolic rate and heart rate variability in coal miners exposed to hypobaric hypoxia in highland workplace.

BackgroundOwing to intermittent/acute exposure to hypobaric hypoxia, highland miners may often suffer, the physiological characteristics between highland and lowland miners, however, are rarely reported. The objective of this study was to compare the physiological characteristics of coal miners working at disparate altitudes.MethodsTwenty-three male coal mining workers acclimating to high altitude for 30 ± 6 days in Tibet (highland group; approx. 4500 m above sea level; 628.39 millibar), and 22 male coal mining workers in Hebei (lowland group; less than 100 m above sea level; 1021.82 millibar) were recruited. Tests were conducted to compare ventilatory parameters, circulation parameters, resting metabolic rate (RMR), and heart rate variability (HRV) indices between the two groups in resting state.ResultsVentilation volume per minute (VE) of the highland group was markedly raised compared to that of the lowland group (11.70 ± 1.57 vs. 8.94 ± 1.97 L/min, p = 0.000). In the meanwhile, O2 intake per heart beat (VO2/HR) was strikingly decreased (3.54 ± 0.54 vs. 4.36 ± 0.69 ml/beat, p = 0.000). Resting metabolic rate relevant to body surface area (RMR/BSA) was found no significant difference between the two groups. Evident reduction in standard deviation of NN intervals (SDNN) and remarkable increase in ratio of low- and high- frequency bands (LF/HF) were manifest in highland miners compared to that of lowland ones (110.82 ± 33.34 vs. 141.44 ± 40.38, p = 0.008 and 858.86 ± 699.24 vs. 371.33 ± 171.46, p = 0.003; respectively).ConclusionsThese results implicate that long-term intermittent exposure to high altitude can lead miners to an intensified respiration, a compromised circulation and a profound sympathetic-parasympathetic imbalance, whereas the RMR in highland miners does not distinctly decline.

Determination of the Effects of Transcutaneous Auricular Vagus Nerve Stimulation on the Heart Rate Variability Using a Machine Learning Pipeline.

Background:We are all aware of day-to-day healthy stress, but, when sustained for long periods, stress is believed to lead to serious physical and mental health issues.Materials and Methods:In this study, we investigated the potential effects of transcutaneous auricular vagus nerve stimulation (taVNS) on stress processing as reflected in the electrocardiogram (ECG)-derived biomarkers of stress adaptability. Stress reflecting biomarkers included a range of heart rate variability metrics: standard deviation of N-N intervals (SDNN), root mean squared of successive differences in heartbeat intervals (RMSSD), low-frequency component, high-frequency component and their ratio (LF, HF, and LF/HF).In addition, we created a machine learning model capable of distinguishing between the stimulated and nonstimulated conditions from the ECG-derive data from various subjects and states. The model consisted of a deep convolutional neural network, which was trained on R-R interval (RRI) data extracted from ECG and time traces of LF, HF, LF/HF, SDNN, and RMSSD.Results:Only LF/HF ratio demonstrated a statistically significant change in response to stimulation. Although the LF/HF ratio is expected to increase during exposure to stress, we have observed that stimulation during exposure to stress counteracts this increase or even reduces the LF/HF ratio. This could be an indication that the vagus nerve stimulation decreases the sympathetic activation during stress inducement.Our Machine Learning model achieved an accuracy of 70% with no significant variations across the three states (baseline, stress, and recovery). However, training an analogous neural network to identify the states (baseline, stress, and recovery) proved to be unsuccessful.Conclusion:Overall, in this study, we showed further evidence of the beneficial effect of taVNS on stress processing. Importantly we have also demonstrated the promising potential of ECG metrics as a biomarker for the development of closed-loop stimulation systems.

Associations between personal noise exposure and heart rate variability were modified by obesity and PM2.5: The study among obese and normal-weight adults (SONA)

Noise pollution has been documented to increase the risks of cardiovascular disorders, which can be predicted by heart rate variability (HRV), nevertheless, there has been limited evidence on the modifiers of noise pollution. Environmental fine particulate matter (PM2.5) and obesity status are both growing major concerns of cardiovascular disease burden. Our study aims to investigate whether these two factors may modify the associations between noise exposure and HRV indices. An investigation was performed on 97 (53 normal-weight and 44 obese) participants aged 18–26 years, with continuous 5-min personal exposure assessment and ambulatory electrocardiogram monitoring for 24 h. This study found that personal exposure to noise was associated with decreased HRV level and imbalanced cardiac autonomic function, as indicated by decreases in standard deviation of normal-to-normal intervals (SDNN), square root of the mean squared differences of successive intervals (rMSSD), the percentage of R-R intervals that differ from each other by more than 50 ms (pNN50), low-frequency (LF) power, high-frequency (HF) power, and increases in LF–HF–Ratio. Stronger associations between personal noise exposure and HRV indices were observed among obese participants and participants with higher PM2.5 exposure levels compared to their counterparts. For SDNN, a 1 dB(A) increment in personal noise exposure at 3h-average was associated with a 1.25% (95%CI: -1.64%, −0.86%) decrease among obese participants, and a 0.11% (95%CI: -0.38%, 0.16%) decrease among normal-weight participants (P for subgroup difference<0.001); and a 0.87% (95%CI: -1.20%, −0.54%) decrease among participants with higher PM2.5 exposure levels, and a 0.22% (95%CI: -0.58%, 0.14%) decrease among participants with lower PM2.5 exposure levels (P for subgroup difference = 0.008). Obesity and PM2.5 may aggravate the adverse effects of noise on HRV, which has implications for targeted prevention of cardiovascular disease burden associated with noise pollution.

Women Emotional, Cognitive and Physiological Modes of Coping with Daily Urban Environments: A Pilot Study.

Studies on the effect of urban environments on human risk to health and well-being tend to focus on either physiological or cognitive and emotional effects. For each of these effects, several indicators have been proposed. They are determined either by a physiological-emotional theory or by a cognitive theory of direct attention. However, the interrelationships between these indices have not been thoroughly investigated in environmental contexts. Recently, a neuro-visceral model that incorporates all three aspects has been proposed. The present article focuses on understanding the mechanism of coping with urban environments. More specifically, we analyze the interrelations among nine of the more commonly used indices that represent the physiological, emotional and cognitive aspects of coping with urban environments. The data were collected in the following four environments: home, park, city center and residential area. The participants were 72 healthy, middle-class mothers with either high school or postgraduate education. They wherein their fertile age (20–35) with average Body Mass Index (BMI) of 22.2 and S.D. of 0.8 (48 Arab Muslims and 24 Jewish). They were recruited in a snowball method. Path analysis and principal component analysis are used in order to identify the interrelations among the physiological, cognitive and emotional indices and the directions of these interrelations. According to the findings, the Autonomic Nervous System (ANS), as measured by Heart Rate Variability (HRV) and primarily the parasympathetic tone (High frequency-HF) is the pivotal mechanism that modulates emotional and cognitive responses to environmental nuisances. The ANS response precedes and may trigger the emotional and the cognitive responses, which are only partially interrelated. It appears that the autonomic balance measured by Standard Deviation of NN interval (SDNN) and HF, the cognitive index of restoration and the emotional indices of discomfort and relaxation are closely interrelated. These seemingly disparate operands work together to form a comprehensive underlying network that apparently causes stress and risk to health in urban environments while restoring health in green environments.

Altered Heart Rate Turbulence and Variability Parameters Predict 1-Year Mortality in Heart Failure with Preserved Ejection Fraction.

Background: Heart failure with preserved ejection fraction (HFpEF) is a complex and heterogeneous clinical syndrome. In the absence of effective and potent treatment strategies, the main challenge in HFpEF management remains the availability of strong predictors of unfavourable outcomes. In our study, we sought to evaluate the potential prognostic value of heart rate turbulence (HRT) and variability (HRV) parameters on mortality in ambulatory HFpEF patients. Methods: This was a case–control study comparing HRT and HRV parameters in HFpEF survivors vs. non-survivors. Patients from the RESPOND Heart Failure Registry with HFpEF who underwent 24 h ECG monitoring (Holter) were included; HRT parameters (i.e., turbulence onset (TO) and turbulence slope (TS)) and HRV parameters (i.e., standard deviation of NN intervals (SDNN)) derived from 24 h Holter ECGs were calculated in patients who died within 12 months, and compared to their age-, gender-, LVEF-, ECHO-, aetiology-, and therapy-matched alive controls. Results: A total of 22 patients (mean age 80 ± 7 years, 18% female, mean LVEF 57 ± 9%) were included in the final analysis. In deceased patients, values of TO were significantly higher, and values of TS and SDNN were significantly lower as compared to survivors. Conclusions: HRT and HRV parameters have the ability to differentiate individuals with HFpEF who are at the greatest risk of unfavourable outcomes. The extent of autonomic disbalance as determined by HRT and HRV could potentially assist in the prognostic assessment and risk stratification of HFpEF patients.

Predictive Value of Heart Rate Variability Indexes for 2-year Prognosis of the Patients after Transcatheter Aortic Valve Replacement.

To explore the prognostic value of the heart rate variability (HRV) index in the patients undergoing transcatheter aortic valve replacement (TAVR). A cohort study. Department of Cardiology, Subei people's Hospital, Yangzhou University, Yangzhou, Jiangsu Province, China, from April 2018 to April 2021. Patients with severe symptomatic aortic stenosis (AS), who were treated with TAVR, were enrolled. All the patients had completed a 24-hour ambulatory electrocardiogram (AECG), and detected HRV within one week before TAVR. All-time domain and frequency domain indexes were analysed. According to the standard deviation of NN intervals (SDNN), the patients were divided into the high HRV group (H-HRV), and the low HRV group (L-HRV). Postoperative cardiac function and major adverse cardiovascular events (MACEs) were observed on follow-up for 24 months. Compared with the H-HRV group, the L-HRV group had a lower preoperative left ventricular ejection fraction (LVEF) [49.0 (42.5, 60.0) vs. 59.5 (51.0, 62.3), p = 0.028] and higher preoperative cardiac troponin I (cTnI) [0.03(0.02, 0.10) vs. 0.02 (0.02, 0.02), p = 0.007]. The incidence of MACEs after TAVR in the L-HRV group was significantly higher than that in the H-HRV group (45.5% vs. 13.6%, p = 0.021). The results of the Kaplan-Meier survival curve also showed that the prognosis of the L-HRV group was worse than that of the H-HRV group (Log Rank = 4.975, p = 0.026). After adjusting for preoperative standard deviation of the average NN intervals (SDANN) or preoperative low-frequency (LF) domain / high-frequency (HF) domain (LF/HF), preoperative HRV still was an independent risk factor for MACEs in AS patients undergoing TAVR [HR 3.718, 95% CI (1.020, 13.548), p = 0.047]. The receiver operating characteristic (ROC) curve suggested that HRV <61.0ms may be a predictor of MACEs in AS patients undergoing TAVR. The sensitivity and specificity were 83.9% and 76.9%, respectively. Preoperative HRV had a good short-term predictive value in AS patients undergoing TAVR. Heart rate variability, Aortic stenosis, Transcatheter aortic valve replacement, Ambulatory electrocardiogram.

Association of preprocedural ultrashort-term heart rate variability with clinical outcomes after transcatheter aortic valve replacement: A nested, case-control, pilot study.

ABSTRACTBackground:Because heart rate variability (HRV) has been linked to important clinical outcomes in various cardiovascular disease states, we investigated whether preprocedural ultrashort-term HRV (UST-HRV) differs between 1-year survivors and nonsurvivors after transcatheter aortic valve replacement (TAVR).Methods:In our single-center, retrospective, nested pilot study, we analyzed data from patients with severe aortic stenosis undergoing TAVR. All patients had preprocedural UST-HRV measured before the administration of any medications or any intervention. To investigate whether preprocedural HRV is associated with 1-year survival, we performed a logistic regression analysis controlling for Kansas City Cardiomyopathy Questionnaire 12 score.Results:In our parent cohort of 100 patients, 42 patients (28 survivors and 14 nonsurvivors) were included for analysis. Root mean square of successive differences (RMSSD) and standard deviation of NN intervals (SDNN) were lower in patients who survived to 1-year post TAVR compared to nonsurvivors [10 (IQR 8–23) vs 23 (IQR 17–33), P = 0.04 and 10 (IQR 7–16) vs 17 (IQR 11–40), P = 0.03, respectively]. Logistic regression demonstrated a trend in the association of preprocedure RMSSD with 1-year mortality and a 5% higher risk of 1-year mortality with each unit increment in UST-HRV using SDNN (OR 1.05; 95%CI 1.01–1.09, P = 0.02).Conclusion:Our data suggest an inverse relationship between preprocedural UST-HRV and 1-year survival post-TAVR. This finding highlights the potential complexity of HRV regulation in chronic vs acute illness. Prospective studies are needed to validate our findings and to determine whether UST-HRV can be used for risk stratification in patients with severe aortic stenosis.

Autonomic Nervous System Indices of Player Readiness During Elite-Level Rugby Union Game-Week Microcycles.

Grainger, A, Heffernan, S, Waldron, M, and Sawczuk, T. Autonomic nervous system indices of player readiness during elite-level rugby union game-week microcycles. J Strength Cond Res 36(11): 3173-3178, 2022-Elite-level rugby union (RU) is a high-intensity contact sport that involves large training and match volumes across a season, which can lead to postmatch fatigue. Autonomic nervous system (ANS) regulation and perceived fatigue have been suggested to relate to measures of training and match load in RU. However, there have been no studies to assess specific ANS variables in elite RU during in-season microcycles. Player readiness during game-week microcycles was measured via heart rate variability (HRV) indices, direct current potential and self-reported well-being among 13, elite, male RU players. To enable comparison, data collection days were categorized in relation to their proximity to match day, ranging from match day minus 3 (MD - 3), to match day plus 3 (MD + 3). Differences between match days were evaluated using general linear models and Cohen's d effect sizes. There were significant differences between MD and MD + 1 for ANS indices (RMSSD p = 0.04, d = -0.66, 95% CI 0.11-1.20; the standard deviation of NN intervals p = 0.04, d = -0.66, 95% CI 0.12-1.20; total power p = 0.05, d = -0.65, 95% CI 0.11-1.20) and wellness measures (readiness p = 0.18; d = -2.33, 95% CI, 1.54-3.13; energy p = 0.02; d = -2.24, 95% CI 1.44-3.03; soreness p = 0.00; d = -2.42, 95% CI 1.63-3.23). Match day plus 3 effects were significantly greater than MD + 1 in several ANS responses, with wellness recovering at a slower time-course than ANS responses. Measures of HRV are dysregulated postmatch, but based on their rapid recovery thereafter, using HRV to assess readiness of elite-level players in RU across a weekly microcycle could be limited and requires further investigation.

Cardiovagal Modulation in Young and Older Male Adults Following Acute Aerobic Exercise.

We compared response patterns of cardiovagal modulation through heart-rate variability (HRV) and baroreflex sensitivity (BRS) indices at 10 and 60 min after an acute bout of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) in active young and older adults. Twelve young (aged 20-40 years) and older (aged 57-76 years) healthy and active male adults performed an isocaloric acute bout of HIIE, MICE, or a non-exercise condition in a randomized order. HRV and BRS indices were analyzed offline with R-R intervals obtained from a supine position. HIIE decreased natural logarithm (Ln) standard deviation of NN intervals (d=-0.53; 95% CI: -0.77 to -0.30 ms, p<0.001), Ln-root mean square of successive differences (d=-0.85; 95% CI: -1.09 to -0.61 ms, p<0.001), Ln-high-frequency power (d=-1.60; 95% CI: -2.11 to -1.10 ms2; p<0.001), and BRS (d=-6.28; 95% CI: -8.91 to -3.64 ms/mmHg, p<0.001) after exercise in young and older adults, whereas MICE did not. Indices returned to baseline after 60 min. We found no evidence of age-associated response patterns in HRV or BRS to a single bout HIIE or MICE in active participants. HIIE reduced cardiovagal modulation in active young and older adults, returning to baseline values 60 min into recovery.