Scaling exponent values as an ordinary function of the ratio of very low frequency to high frequency powers in heart rate variability over various sleep stages

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

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Coarse-graining spectral analysis: new method for studying heart rate variability

Journal of Applied Physiology ◽

10.1152/jappl.1991.71.3.1143 ◽

1991 ◽

Vol 71 (3) ◽

pp. 1143-1150 ◽

Cited By ~ 229

Author(s):

Y. Yamamoto ◽

R. L. Hughson

Keyword(s):

Heart Rate ◽

Time Series ◽

Heart Rate Variability ◽

Spectral Analysis ◽

High Frequency ◽

Low Frequency ◽

Scale Invariant ◽

Very Low Frequency ◽

Frequency Components ◽

Harmonic Components

Heart rate variability (HRV) spectra are typically analyzed for the components related to low- (less than 0.15 Hz) and high- (greater than 0.15 Hz) frequency variations. However, there are very-low-frequency components with periods up to hours in HRV signals, which might smear short-term spectra. We developed a method of spectral analysis suitable for selectively extracting very-low-frequency components, leaving intact the low- and high-frequency components of interest in HRV spectral analysis. Computer simulations showed that those low-frequency components were well characterized by fractional Brownian motions (FBMs). If the scale invariant, or self-similar, property of FBMs is considered a new time series (x′) was constructed by sampling only every other point (course graining) of the original time series (x). Evaluation of the cross-power spectra between these two (Sxx′) showed that the power of the FBM components was preserved, whereas that of the harmonic components vanished. Subtraction of magnitude of Sxx from the autopower spectra of the original sequence emphasized only the harmonic components. Application of this method to HRV spectral analyses indicated that it might enable one to observe more clearly the low- and high-frequency components characteristic of autonomic control of heart rate.

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DYNAMICS OF HEART RATE VARIABILITY UNDER THE INFLUENCE OF COURSE YOGA BREATHING EXERCISES ON HEALTHY YOUNG PEOPLE

Wiadomości Lekarskie ◽

10.36740/wlek201904120 ◽

2019 ◽

Vol 72 (4) ◽

pp. 613-616 ◽

Cited By ~ 1

Author(s):

Nataliia I. Sheiko ◽

Volodymyr P. Feketa

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

High Frequency ◽

Cardiac Rhythm ◽

Low Frequency ◽

Frequency Component ◽

High Frequency Component ◽

Regulatory Activity ◽

Biological Feedback ◽

Very Low Frequency

Introduction: Heart rate variability is a highly informative non-invasive method of research not only for the functional state of the cardiovascular system and also for the integrative regulatory activity of the autonomic nervous system. The positive effect of diaphragmatic breathing is positive in the mode of biological feedback using portable devices, but there is little evidence of the use of yoga breathing gymnastics in order to influence the heart rate variability. The aim: To compare the possibilities of using courses of breathing gymnastics of yogis and diaphragmatic breathing sessions in the mode of biological feedback using a portable device. Materials and methods: The study involved 70 practically healthy foreigners, who were divided into 2 groups of 35 people. Participants of the 1st group daily engage in respiratory exercises pranayama for 15 minutes in 1 month. Participants in the 2nd group used the MyCalmBeat portable device. Heart rate variability was registered by using the computer diagnostic complex “CardioLab” (“KhAI-Medika”, Ukraine). Results: In both groups there was similar dynamics of heart rate variability indices, but its severity was different. The common integral effect was a significant growth of heart rate variability both according to statistical and spectral indicators – total power increased, as well as high-frequency component. The power of the very-low frequency waves has probably decreased only in the group with the device. In the percentage structure of the cardiac rhythm spectrum, the specific weight of very-low frequency component and the percentage of high-frequency component increased. Conclusions: Respiratory gymnastics yoga for 15 minutes daily contributes to the growth of heart rate variability through the suppression of the central link (very-low frequency component) of regulation of cardiac rhythm and increased activity of parasympathetic influences (high-frequency component), as well as the redistribution of regulatory activity of the central nervous system between the central and peripheral links of regulation of the cardiac rhythm in favor of the latter.

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Very-Low-Frequency Heart Rate Variability: Mental Stressors in Tetraplegics

PsycEXTRA Dataset ◽

10.1037/e642612010-001 ◽

2010 ◽

Author(s):

N. Lynn De Paur

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Low Frequency ◽

Very Low Frequency ◽

Mental Stressors

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The Influence ofNrf2on Cardiac Responses to Environmental Stressors

Oxidative Medicine and Cellular Longevity ◽

10.1155/2013/901239 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Reuben Howden ◽

Eva Gougian ◽

Marcus Lawrence ◽

Samantha Cividanes ◽

Wesley Gladwell ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

High Frequency ◽

Low Frequency ◽

Therapeutic Strategies ◽

Environmental Stressors ◽

Total Power ◽

Airborne Pollutants ◽

Cardiac Responses

Nrf2protects the lung from adverse responses to oxidants, including 100% oxygen (hyperoxia) and airborne pollutants like particulate matter (PM) exposure, but the role ofNrf2on heart rate (HR) and heart rate variability (HRV) responses is not known. We hypothesized that genetic disruption ofNrf2would exacerbate murine HR and HRV responses to severe hyperoxia or moderate PM exposures.Nrf2-/-andNrf2+/+mice were instrumented for continuous ECG recording to calculate HR and HRV (low frequency (LF), high frequency (HF), and total power (TP)). Mice were then either exposed to hyperoxia for up to 72 hrs or aspirated with ultrafine PM (UF-PM). Compared to respective controls, UF-PM induced significantly greater effects on HR (P<0.001) and HF HRV (P<0.001) inNrf2-/-mice compared toNrf2+/+mice.Nrf2-/-mice tolerated hyperoxia significantly less thanNrf2+/+mice (~22 hrs;P<0.001). Reductions in HR, LF, HF, and TP HRV were also significantly greater inNrf2-/-compared toNrf2+/+mice (P<0.01). Results demonstrate thatNrf2deletion increases susceptibility to change in HR and HRV responses to environmental stressors and suggest potential therapeutic strategies to prevent cardiovascular alterations.

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Effect of Acupuncture on Heart Rate Variability: A Systematic Review

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2014/819871 ◽

2014 ◽

Vol 2014 ◽

pp. 1-19 ◽

Cited By ~ 22

Author(s):

Joanne W. Y. Chung ◽

Vincent C. M. Yan ◽

Hongwei Zhang

Keyword(s):

Systematic Review ◽

Heart Rate ◽

Heart Rate Variability ◽

High Frequency ◽

Healthy Subjects ◽

Keyword Search ◽

Data Extraction ◽

Meta Analysis ◽

Low Frequency ◽

Control Group

Aim.To summarize all relevant trials and critically evaluate the effect of acupuncture on heart rate variability (HRV).Method.This was a systematic review with meta-analysis. Keyword search was conducted in 7 databases for randomized controlled trials (RCTs). Data extraction and risk of bias were done.Results.Fourteen included studies showed a decreasing effect of acupuncture on low frequency (LF) and low frequency to high frequency ratio (LF/HF ratio) of HRV for nonhealthy subjects and on normalized low frequency (LF norm) for healthy subjects. The overall effect was in favour of the sham/control group for high frequency (HF) in nonhealthy subjects and for normalized high frequency (HF norm) in healthy subjects. Significant decreasing effect on HF and LF/HF ratio of HRV when acupuncture was performed on ST36 among healthy subjects and PC6 among both healthy and nonhealthy subjects, respectively.Discussion.This study partially supports the possible effect of acupuncture in modulating the LF of HRV in both healthy and nonhealthy subjects, while previous review reported that acupuncture did not have any convincing effect on HRV in healthy subjects. More published work is needed in this area to determine if HRV can be an indicator of the therapeutic effect of acupuncture.

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Modulation of Neurocardiac Function by Oesophageal Stimulation in Humans

Clinical Science ◽

10.1042/cs0920167 ◽

1997 ◽

Vol 92 (2) ◽

pp. 167-174 ◽

Cited By ~ 42

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.

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Sleep Stage Assessment Using Power Spectral Indices of Heart Rate Variability With a Simple Algorithm

Biological Research For Nursing ◽

10.1177/1099800412440498 ◽

2012 ◽

Vol 15 (3) ◽

pp. 264-272 ◽

Cited By ~ 12

Author(s):

Keiko Tanida ◽

Masashi Shibata ◽

Margaret M. Heitkemper

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Sleep Stage ◽

Sleep Onset ◽

Low Frequency ◽

Simple Algorithm ◽

Sleep Stages ◽

Spectral Indices ◽

Current Form ◽

Power Spectral

Clinical researchers do not typically assess sleep with polysomnography (PSG) but rather with observation. However, methods relying on observation have limited reliability and are not suitable for assessing sleep depth and cycles. The purpose of this methodological study was to compare a sleep analysis method based on power spectral indices of heart rate variability (HRV) data to PSG. PSG and electrocardiography data were collected synchronously from 10 healthy women (ages 20–61 years) over 23 nights in a laboratory setting. HRV was analyzed for each 60-s epoch and calculated at 3 frequency band powers (very low frequency [VLF]-hi: 0.016–0.04 Hz; low frequency [LF]: 0.04–0.15 Hz; and high frequency [HF]: 0.15–0.4 Hz). Using HF/(VLF-hi + LF + HF) value, VLF-hi, and heart rate (HR) as indices, an algorithm to categorize sleep into 3 states (shallow sleep corresponding to Stages 1 & 2, deep sleep corresponding to Stages 3 & 4, and rapid eye movement [REM] sleep) was created. Movement epochs and time of sleep onset and wake-up were determined using VLF-hi and HR. The minute-by-minute agreement rate with the sleep stages as identified by PSG and HRV data ranged from 32 to 72% with an average of 56%. Longer wake after sleep onset (WASO) resulted in lower agreement rates. The mean differences between the 2 methods were 2 min for the time of sleep onset and 6 min for the time of wake-up. These results indicate that distinguishing WASO from shallow sleep segments is difficult using this HRV method. The algorithm's usefulness is thus limited in its current form, and it requires additional modification.

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