Investigation of statistical characteristics of interaction between the low-frequency oscillations in heart rate variability and photoplethysmographic waveform variability in healthy subjects and myocardial infarction patients

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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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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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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Low Heart Rate Variability Predicts Stroke and Other Complications in the First Six Postoperative Months After a Hip Fracture Operation

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.640970 ◽

2021 ◽

Vol 8 ◽

Author(s):

Gernot Ernst ◽

Leiv Otto Watne ◽

Frede Frihagen ◽

Torgeier Bruun Wyller ◽

Andreas Dominik ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Rate ◽

Heart Rate Variability ◽

Hip Fracture ◽

Low Frequency ◽

Total Power ◽

Mortality Data ◽

Low Frequency Power ◽

Frequency Power

Background: One-year mortality after hip fractures is underestimated and is reported as 25%. An improved risk stratifying could contribute to a better follow up of these patients. Heart Rate Variability (HRV) is an easy point-of-care investigation and is been used in cardiology, endocrinology, and perioperative care. This observational study intended to explore relevant associations between HRV parameters and 6-months mortality and morbidity after a hip fracture.Methods: One hundred and sixty-five patients admitted to two hospitals were included, and short-time HRV measurements (5 min, and 10 min at the two hospitals, respectively) were obtained. Mortality data were gathered by means of the Norwegian central address register. Patients, close relatives of patients, and in some cases their general physicians or nursery home physicians were interviewed 6 months postoperatively regarding the incidence of pneumonia, cardiac events, or stroke.Results: One and hundred fifty-seven (95.2%) patients were followed up after 6 months post-surgery. Twenty-one (13%) died during this period. Twenty patients (13%) developed pneumonia, eight (5 %) stroke, and four (2%) myocardial infarction. No HRV parameter was associated with 6-month general mortality. However, patients who developed stroke had significantly lower High Frequency Power (HF, p < 0.001) and lower Very Low Frequency Power (VLF, p = 0.003) at inclusion compared to patients without complications. Patients who developed pneumonia had at the inclusion lower root mean square of successive differences (RMSSD, p = 0.044). Patients with a history of coronary heart disease (n = 41) showed a mortality of 7%. Mortality in this group was associated with standard deviation of beat-to-beat intervals (SDNN, p = 0.006), Total Power (TP, p = 0.009), HF (p = 0.026), and Low Frequency Power (LF, p = 0.012). Beta-blocker intake was associated with lower heart rate, but not with differences in HRV parameters.Conclusion: In this exploratory study, we present for the first-time significant associations between different preoperative HRV parameters and stroke, myocardial infarction, and pneumonia during a 6-month period after hip fracture. HRV might be a simple and effective tool to identify patients at risk that would warrant better follow-up.

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Low heart rate variability predicts stroke and other complications in the first six postoperative months after a hip fracture operation.

10.21203/rs.2.13297/v1 ◽

2019 ◽

Author(s):

Gernot Ernst ◽

Leiv Otto Watne ◽

Frede Frihagen ◽

Torgeir Bruun Wyller ◽

Andreas Dominik ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Rate ◽

Heart Rate Variability ◽

Hip Fracture ◽

Low Frequency ◽

Total Power ◽

Mortality Data ◽

Low Frequency Power ◽

Frequency Power

Abstract Background 1-year mortality after hip fractures is underestimated and is reported as 25%. An improved risk stratifying could contribute to a better follow up of these patients. Heart Rate Variability (HRV) is an easy point-of-care investigation and is used in cardiology, endocrinology and perioperative care. This observational study intended to explore relevant associations between HRV parameters and 6-months mortality and morbidity after a hip fracture. Methods 165 patients admitted to two hospitals were included and short-time HRV measurements were obtained. Mortality data were gathered from the Norwegian central address register. Patients, close relatives of patients and in some cases their general physicians or nursery home physicians were interviewed six months postoperatively regarding the incidence of pneumonia, cardiac events or stroke. Results 157 (95.2%) patients were followed up after six months. 21 (13%) died during this period. Twenty patients (13%) developed pneumonia, eight (5%) stroke and four (2%) myocardial infarction. No HRV parameter was associated with six-month general mortality. However, patients who developed stroke, had significantly lower High Frequency Power (HF, p< 0.001) and lower Very Low Frequency Power (VLF, p=0.003) at inclusion compared to patients without complications. Patients who developed pneumonia had at inclusion lower root mean square of successive differences (RMSSD, p = 0.044). Patients with a history of coronary heart disease (n = 41) showed a mortality of 7%. Mortality in this group was associated with the standard deviation of the NN intervals (SDNN, p = 0.006), Total Power (TP, p = 0.009), HF (p = 0.026), and Low Frequency Power (LF, p = 0.012). Beta-blocker intake was not associated with differences in HRV parameters. Conclusions We present for the first time significant associations between different preoperative HRV parameters and stroke, myocardial infarction and pneumonia during a 6-month period after hip fracture. HRV might be a simple and effective tool to identify patients at risk that would warrant better follow-up.

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