scholarly journals Can Heart Rate Variability (HRV) Be Used as a Biomarker of Thermal Comfort for Mine Workers?

2021 ◽  
Vol 18 (14) ◽  
pp. 7615
Author(s):  
Guoshan Wu ◽  
Heqing Liu ◽  
Shixian Wu ◽  
Guanglei Liu ◽  
Caihang Liang
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Low Frequency ◽  
Predictive Biomarkers ◽  
Strong Negative Correlation ◽  
Significant Difference ◽  
Low Frequency Power ◽  
Mine Workers

This study aimed to determine whether heart rate variability (HRV) can express the thermal comfort of mine workers. Eight subjects ran on a treadmill (5.5 km/h) to simulate heavy labor in three kinds of mining environments (22 °C/90%, 26 °C/90%, 30 °C/90%), respectively. Based on the measured electrocardiogram (ECG) data, the HRV of the subjects was calculated. The results showed that the HRV indices changed obviously under different temperature environments. In the neutral and hot environment, except for the LF, TP and LF/HF, there were significant differences in each index. However, there was no significant difference between the cold and neutral environments. The R-R intervals, the very low-frequency power (VLF), pNN20 and SampEN had strong negative correlation with the thermal sensation of people from sitting to work (ρ < −0.700). These indices may be used as thermal comfort predictive biomarkers of mine workers.

Modulation of Neurocardiac Function by Oesophageal Stimulation in Humans

1997 ◽  
Vol 92 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Gervais Tougas ◽  
Markad Kamath ◽  
Geena Watteel ◽  
Debbie Fitzpatrick ◽  
Ernest L. Fallen ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Power Spectrum ◽  
High Frequency ◽  
Low Frequency ◽  
Sensory Stimulation ◽  
Sensory Stimuli ◽  
Autonomic Reflexes ◽  
Low Frequency Power ◽  
Beat Heart

1. The heart and the oesophagus have similar sensory pathways, and sensations originating from the oesophagus are often difficult to differentiate from those of cardiac origin. We hypothesized that oesophageal sensory stimuli could alter neurocardiac function through autonomic reflexes elicited by these oesophageal stimuli. In the present study, we examined the neurocardiac response to oesophageal stimulation and the effects of electrical and mechanical oesophageal stimulation on the power spectrum of beat-to-beat heart rate variability in male volunteers. 2. In 14 healthy volunteers, beat-to-beat heart rate variability was compared at rest and during oesophageal stimulation, using either electrical (200 μs, 16 mA, 0.2 Hz) or mechanical (0.5 s, 14 ml, 0.2 Hz) stimuli. The power spectrum of beat-to-beat heart rate variability was obtained and its low- and high-frequency components were determined. 3. Distal oesophageal stimulation decreased heart rate slightly (both electrical and mechanical) (P < 0.005), and markedly altered heart rate variability (P < 0.001). Both electrical and mechanical oesophageal stimulation increased the absolute and normalized area of the high-frequency band within the power spectrum (P < 0.001), while simultaneously decreasing the low-frequency power (P < 0.005). 4. In humans, oesophageal stimulation, whether electrical or mechanical, appears to amplify respiratory-driven cardiac vagoafferent modulation while decreasing sympathetic modulation. The technique provides access to vagoafferent fibres and thus may yield useful information on the autonomic effects of visceral or oesophageal sensory stimulation.

The Comparisons of Heart Rate Variability and Perceived Exertion During Simulated Cycling with Various Viewing Devices

2008 ◽  
Vol 17 (6) ◽  
pp. 575-583 ◽  
Author(s):  
Shih-Fong Huang ◽  
Po-Yi Tsai ◽  
Wen-Hsu Sung ◽  
Chih-Yung Lin ◽  
Tien-Yow Chuang
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Perceived Exertion ◽  
Low Frequency ◽  
Control Group ◽  
Threshold Intensity ◽  
Power Spectral ◽  
Significant Difference

Sympathovagal modulation during immersion in a virtual environment is an important influence on human performance of a task. The aim of this study is to investigate sympathovagal modulation using heart rate variability and perceived exertion during exercise in a virtual reality (VR) environment. Sixteen young healthy volunteers were tested while using a stationary bicycle and maintained at an anaerobic threshold intensity for exercise sessions of approximately 10 min duration. Four randomized viewing alternatives were provided including desktop monitor, projector, head mounted device (HMD), and no simulation display. The “no simulation display” served as the control group. A quick ramp exercise test was conducted and maintained at an anaerobic threshold intensity for each session to evaluate power spectral density and rating of perceived exertion (RPE). The sampled heart rate data were rearranged by cubic spline interpolation into power spectrums spanning the ultra-low frequency (ULF) to high frequency (HF) range. A significant difference was found between the no-display and projector groups for total power (TP) and very low frequency (VLF) components. In particular, there was a significant difference when comparing HMD and no-display exercise RPE curves within 6 min of cycling and at the termination of the exercise. A significant difference was also achieved in projector vs. control group comparison at the termination of the exercise. Our results indicate that the use of HMD and the projected VR during cycling can reduce the TP and VLF power spectral density through a proposed decrease in the renin-angiotensin system, with the implication that this humoral effect may enable anaerobic exercise for longer durations through a reduction in sympathetic tone and subsequent increased blood flow to the muscles.

Heart rate variability and dissociation in panic disorder

2011 ◽  
Vol 26 (S2) ◽  
pp. 147-147
Author(s):  
T. Diveky ◽  
D. Kamaradova ◽  
A. Grambal ◽  
K. Latalova ◽  
J. Prasko ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Panic Disorder ◽  
Frequency Band ◽  
High Frequency ◽  
Power Spectra ◽  
Low Frequency ◽  
Very Low Frequency ◽  
Significant Difference ◽  
Before And After

The aim of our study is to measure very low frequency band (VLF), low frequency band (LF) and high frequency band (HF) components of R-R interval during orthostatic experiment in panic disorder patients before and after treatment.MethodsWe assessed heart rate variability in 19 patients with panic disorder before and after 6-weeks treatment with antidepressants combined with CBT and 18 healthy controls. They were regularly assessed on the CGI, BAI and BDI. Heart rate variability was assessed during 5 min standing, 5 min supine and 5 min standing positions before and after the treatment. Power spectra were computed using a fast Fourier transformation for very low frequency - VLF (0.0033 - 0.04 Hz), low-frequency - LF (0.04-0.15 Hz) and high frequency - HF (0.15-0.40 Hz) powers.Results19 panic disorder patients entered a 6-week open-label treatment study with combination of SSRI and cognitive behavioral therapy. A combination of CBT and pharmacotherapy proved to be the effective treatment of patients. They significantly improved in all rating scales. There were highly statistical significant differences between panic patients and control group in all components of power spectral analysis in 2nd and in two component of 3rd (LF and HF in standing) positions. There was also statistically significant difference between these two groups in LF/HF ratio in supine position (2nd). During therapy there was tendency to increasing values in all three positions in components of HRV power spectra, but there was only statistically significant increasing in HF1 component.Supported by project IGA MZ ČR NS 10301-3/2009

Normalized Low Frequency Power of Heart Rate Variability Correlates Negatively With the SOFA Score in Severe Sepsis and Septic Shock

CHEST Journal ◽  
2011 ◽  
Vol 140 (4) ◽  
pp. 427A
Author(s):  
Subhasis Behera ◽  
Samuel Brown ◽  
Jason Jones ◽  
Michael Lanspa ◽  
Kathryn Kuttler ◽  
...  
Keyword(s):  
Heart Rate ◽  
Septic Shock ◽  
Heart Rate Variability ◽  
Severe Sepsis ◽  
Sofa Score ◽  
Low Frequency ◽  
Low Frequency Power ◽  
Sepsis And Septic Shock ◽  
Frequency Power

Supine low-frequency power of heart rate variability reflects baroreflex function, not cardiac sympathetic innervation

2009 ◽  
Vol 76 (4 suppl 2) ◽  
pp. S51-S59 ◽  
Author(s):  
Jeffrey P. Moak ◽  
David S. Goldstein ◽  
Basil A. Eldadah ◽  
Ahmed Saleem ◽  
Courtney Holmes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Innervation ◽  
Low Frequency ◽  
Cardiac Sympathetic Innervation ◽  
Baroreflex Function ◽  
Low Frequency Power ◽  
Frequency Power

Reproducibility of Heart Rate Variability Measures in Patients with Chronic Heart Failure

1996 ◽  
Vol 91 (4) ◽  
pp. 391-398 ◽  
Author(s):  
Piotr Ponikowski ◽  
Massimo Piepoli ◽  
Aham A. Amadi ◽  
Tuan Peng Chua ◽  
Derek Harrington ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Chronic Heart Failure ◽  
Time Domain ◽  
Low Frequency ◽  
Variation Coefficient ◽  
Very Low Frequency ◽  
Low Frequency Power ◽  
Frequency Power

1. In patients with chronic heart failure, heart rate variability is reduced with relative preservation of very-low-frequency power (< 0.04 Hz). Heart rate variability has been measured without acceptable information on its stability and the optimal recording periods for enhancing this reproducibility. 2. To this aim and to establish the optimal length of recording for the evaluation of the very-low-frequency power, we analysed 40, 20, 10 and 5 min ECG recordings obtained on two separate occasions in 16 patients with chronic heart failure. The repeatability coefficient and the variation coefficient were calculated for the heart rate variability parameters, in the time-domain (mean RR, SDRR and pNN50), and in the frequency-domain: very low frequency (< 0.04 Hz), low frequency (0.04–0.15 Hz), high frequency (0.15–0.40 Hz), total power (0–0.5 Hz). 3. Mean RR remained virtually identical over time (variation coefficient 8%). The reproducibility of time-domain (variation coefficient 25–139%) and of spectral measures (variation coefficient 45–111%) was very low. The stability of the heart rate variability parameters was only apparently improved after square root and after log transformation. 4. Very-low-frequency values derived from 5 and 10 min intervals were significantly lower than those calculated from 40 and 20 min intervals (P < 0.005). Discrete very-low-frequency peaks were detected in 11 out of 16 patients on the first 40, 20 and 10 min recording, but only in seven out of 16 when 5 min segments were analysed. 5. The reproducibility of both time or frequency-domain measures of heart rate variability in patients with chronic heart failure may vary significantly. Square root or log-transformed parameters may be considered rather than absolute units in studies assessing the influence of management on heart rate variability profile. Recordings of at least 20 min in stable, controlled conditions are to be recommended to optimize signal acquisition in patients with chronic heart failure, if very-low-frequency power in particular is to be studied.

Low-frequency component of the heart rate variability spectrum: a poor marker of sympathetic activity

1999 ◽  
Vol 276 (1) ◽  
pp. H215-H223 ◽  
Author(s):  
Melanie S. Houle ◽  
George E. Billman
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Ventricular Fibrillation ◽  
Sympathetic Activity ◽  
Low Frequency ◽  
Frequency Component ◽  
Atropine Sulfate ◽  
Low Frequency Power ◽  
Heart Rate Variability Spectrum ◽  
Frequency Power

The low-frequency component of the heart rate variability spectrum (0.06–0.10 Hz) is often used as an accurate reflection of sympathetic activity. Therefore, interventions that enhance cardiac sympathetic drive, e.g., exercise and myocardial ischemia, should elicit increases in the low-frequency power. Furthermore, because an enhanced sympathetic activation has been linked to an increased propensity for malignant arrhythmias, one might also predict a greater low-frequency power in animals that are susceptible to ventricular fibrillation than in resistant animals. To test these hypotheses, a 2-min coronary occlusion was made during the last minute of exercise in 71 dogs with healed myocardial infarctions: 43 had ventricular fibrillation (susceptible) and 28 did not experience arrhythmias (resistant). Exercise or ischemia alone provoked significant heart rate increases in both groups of animals, with the largest increase in the susceptible animals. These heart rate increases were attenuated by β-adrenergic receptor blockade. Despite the sympathetically mediated increases in heart rate, the low-frequency power decreased, rather than increased, in both groups, with the largest decrease again in the susceptible animals: 4.0 ± 0.2 (susceptible) vs. 4.1 ± 0.2 ln ms2 (resistant) in preexercise control and 2.2 ± 0.2 (susceptible) vs. 2.9 ± 0.2 ln ms2 (resistant) at highest exercise level. In a similar manner the parasympathetic antagonist atropine sulfate elicited significant reductions in the low-frequency power. Although sympathetic nerve activity was not directly recorded, these data suggest that the low-frequency component of the heart rate power spectrum probably results from an interaction of the sympathetic and parasympathetic nervous systems and, as such, does not accurately reflect changes in the sympathetic activity.

Heart Rate Variability as a Predictor of Cardiac Dysrhythmias During Weaning From Mechanical Ventilation

2015 ◽  
Vol 24 (2) ◽  
pp. 118-127 ◽  
Author(s):  
Muna H. Hammash ◽  
Debra K. Moser ◽  
Susan K. Frazier ◽  
Terry A. Lennie ◽  
Melanie Hardin-Pierce
Keyword(s):  
Heart Rate ◽  
Mechanical Ventilation ◽  
Heart Rate Variability ◽  
Low Frequency ◽  
Weaning From Mechanical Ventilation ◽  
Cardiac Dysrhythmias ◽  
Ectopic Beats ◽  
The Mean ◽  
Low Frequency Power ◽  
Frequency Power

BackgroundWeaning from mechanical ventilation to spontaneous breathing is associated with changes in the hemodynamic and autonomic nervous systems that are reflected by heart rate variability. Although cardiac dysrhythmias are an important manifestation of hemodynamic alterations, the impact of heart rate variability on the occurrence of dysrhythmias during weaning has not been specifically studied.ObjectivesTo describe differences in heart rate variability spectral power and occurrence of cardiac dysrhythmias at baseline and during the initial trial of weaning from mechanical ventilation and to evaluate the impact of heart rate variability during weaning on occurrence of dysrhythmias.MethodContinuous 3-lead electrocardiographic recordings were collected from 35 patients receiving mechanical ventilation for 24 hours at baseline and during the initial weaning trial. Heart rate variability was evaluated by using spectral power analysis.ResultsLow-frequency power increased (P = .04) and high-frequency and very-low-frequency power did not change during weaning. The mean number of supraventricular ectopic beats per hour during weaning was higher than the mean at baseline (P &lt; .001); the mean of ventricular ectopic beats did not change. Low-frequency power was a predictor of ventricular and supraventricular ectopic beats during weaning (P &lt; .001). High-frequency power was predictive of ventricular and supraventricular (P = .02) ectopic beats during weaning. Very-low-frequency power was predictive of ventricular ectopic beats (P &lt; .001) only.ConclusionHeart rate variability power spectra during weaning were predictive of dysrhythmias. (American Journal of Critical Care. 2015;24:118–127)

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