Dynamics of spectral indices of the heart rate variability and the photoplethysmogram and synchronization of the low-frequency oscillations in healthy subjects during the tilt test

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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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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Estimation of Delay Times in Coupling Between Autonomic Regulatory Loops of Human Heart Rate and Blood Flow Using Phase Dynamics Analysis

The Open Hypertension Journal ◽

10.2174/1876526201709010016 ◽

2017 ◽

Vol 9 (1) ◽

pp. 16-22 ◽

Cited By ~ 1

Author(s):

Vladimir S Khorev ◽

Anatoly S Karavaev ◽

Elena E Lapsheva ◽

Tatyana A Galushko ◽

Mikhail D Prokhorov ◽

...

Keyword(s):

Heart Rate ◽

Delay Time ◽

Healthy Subjects ◽

Low Frequency ◽

Phase Dynamics ◽

Oscillatory Systems ◽

Low Frequency Oscillations ◽

Delay Times ◽

The Difference ◽

Regulatory Loop

Objective: We assessed the delay times in the interaction between the autonomic regulatory loop of Heart Rate Variability (HRV) and autonomic regulatory loop of photoplethysmographic waveform variability (PPGV), showing low-frequency oscillations. Material and Methods: In eight healthy subjects aged 25–30 years (3 male, 5 female), we studied at rest (in a supine position) the simultaneously recorded two-hour signals of RR intervals (RRIs) chain and finger photoplethysmogram (PPG). To extract the low-frequency components of RRIs and PPG signal, associated with the low-frequency oscillations in HRV and PPGV with a frequency of about 0.1 Hz, we filtered RRIs and PPG with a bandpass 0.05-0.15 Hz filter. We used a method for the detection of coupling between oscillatory systems, based on the construction of predictive models of instantaneous phase dynamics, for the estimation of delay times in the interaction between the studied regulatory loops. Results: Averaged value of delay time in coupling from the regulatory loop of HRV to the loop of PPGV was 0.9±0.4 seconds (mean ± standard error of the means) and averaged value of delay time in coupling from PPGV to HRV was 4.1±1.1 seconds. Conclusion: Analysis of two-hour experimental time series of healthy subjects revealed the presence of delay times in the interaction between regulatory loops of HRV and PPGV. Estimated delay time in coupling regulatory loops from HRV to PPGV was about one second or even less, while the delay time in coupling from PPGV to HRV was about several seconds. The difference in delay times is explained by the fact that PPGV to HRV response is mediated through the autonomic nervous system (baroreflex), while the HRV to PPGV response is mediated mechanically via cardiac output.

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Mathematical modeling of the cardiovascular autonomic control in healthy subjects during a passive head-up tilt test

Scientific Reports ◽

10.1038/s41598-020-71532-7 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Yurii M. Ishbulatov ◽

Anatoly S. Karavaev ◽

Anton R. Kiselev ◽

Margarita A. Simonyan ◽

Mikhail D. Prokhorov ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cardiovascular System ◽

Healthy Subjects ◽

Low Frequency ◽

Tilt Test ◽

Peripheral Vascular ◽

Control Loops ◽

Head Up Tilt ◽

Head Up Tilt Test

Abstract A mathematical model is proposed for the autonomic control of cardiovascular system, which takes into account two separated self-exciting sympathetic control loops of heart rate and peripheral vascular tone. The control loops are represented by self-exciting time-delay systems and their tone depends on activity of the aortic, carotid, and lower-body baroreceptors. The model is used to study the dynamics of the adaptive processes that manifest in a healthy cardiovascular system during the passive head-up tilt test. Computer simulation provides continuous observation of the dynamics of the indexes and variables that cannot be measured in the direct experiment, including the noradrenaline concentration in vessel wall and heart muscle, tone of the sympathetic and parasympathetic control, peripheral vascular resistance, and blood pressure. In the supine and upright positions, we estimated the spectral characteristics of the model variables, especially in the low-frequency band, and the original index of total percent of phase synchronization between the low-frequency oscillations in heart rate and blood pressure signals. The model demonstrates good quantitative agreement with the dynamics of the experimentally observed indexes of cardiovascular system that were averaged for 50 healthy subjects.

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Phase locked loop algorithm of longterm ECG induces low frequency oscillations in heart rate variability spectra

Proceedings of Computers in Cardiology Conference ◽

10.1109/cic.1993.378407 ◽

2002 ◽

Author(s):

A.W. Frey ◽

M. Dambacher ◽

K. Theisen

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Low Frequency ◽

Phase Locked Loop ◽

Low Frequency Oscillations

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Circadian rhythm of spectral indices of heart rate variability in healthy subjects

Journal of Electrocardiology ◽

10.1016/j.jelectrocard.2005.01.012 ◽

2005 ◽

Vol 38 (3) ◽

pp. 239-243 ◽

Cited By ~ 38

Author(s):

Andrzej Bilan ◽

Agnieszka Witczak ◽

Robert Palusiński ◽

Wojciech Myśliński ◽

Janusz Hanzlik

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Circadian Rhythm ◽

Healthy Subjects ◽

Spectral Indices

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Simultaneous Beat-To-Beat Heart Rate And Systolic Blood Pressure Variability In Patients With And Without Neurally Mediated Syncope

10.21203/rs.3.rs-569717/v1 ◽

2021 ◽

Author(s):

Amirhossein Akbarzadeh ◽

Fariborz Akbarzadeh ◽

Babak Kazemi

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Systolic Blood Pressure ◽

Low Frequency ◽

Tilt Test ◽

Control Group ◽

Case Group ◽

Spectral Indices ◽

Neurally Mediated Syncope ◽

Head Up Tilt Test

Abstract Background: Autonomic changes play an essential role in the genesis of neurally mediated syncope (NMS). The aim of this study was to compare the changes of the autonomic nervous system (ANS) by measuring spectral indices of beat-to-beat systolic blood pressure and heart rate variability (SBPV and HRV) in ranges of low frequency (LF), high frequency (HF), and the LF/HF ratio during head-up tilt test (HUTT) in patients with and without a syncope response. Methods: In this case-control study of 46 patients with a suspected history of unexplained syncope, data were recorded separately during the typical three phases of HUTT. Patients who developed syncope were designated as the case group and the rest as the control group. Results: Thirty one patients experienced syncope during HUTT. Resting HRV and SBPV indices were significantly lower in cases than controls. After tilting in the syncope group, both HF and LF powers of SBPV showed a significant and gradual decrease. LF/HF in HRV increased in both groups similarly during the test but in SBPV, mainly driven by oscilations in its LF power, it increased significantly more during the first two phases of the test in syncope patients only to paradoxically decrease during active tilt (p< 0.001). Conclusion: Our findings show an abnormal autonomic function in patients with syncope, both at rest and tilting. Fluctuations of spectral indices of beat-to-beat SBPV, a potential noval index of pure sympathetic activity, show an exaggerated response during tilt and its withdrawal before syncope.

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