A potential method for ambulatory wearables to evaluate the central autonomic network: simultaneous measurement of prefrontal fNIRS and high frequency heart rate variability (Conference Presentation)

2020 ◽  
Author(s):  
Emma Condy ◽  
Bruce H. Friedman ◽  
John Millerhagen ◽  
Amir H. Gandjbakhche
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Simultaneous Measurement ◽  
High Frequency ◽  
Potential Method ◽  
Central Autonomic Network

scholarly journals Effect of Hypoglycemia on Heart Rate Variability in People with Type 1 Diabetes and Impaired Awareness of Hypoglycemia

2021 ◽  
pp. 193229682110074
Author(s):  
Mats Koeneman ◽  
Marleen Olde Bekkink ◽  
Lian van Meijel ◽  
Sebastian Bredie ◽  
Bastiaan de Galan
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Sympathetic Activity ◽  
Elevated Risk ◽  
Wilcoxon Rank Sum Test ◽  
Impaired Awareness ◽  
Induced Changes ◽  
Measurable Change

Background: People with impaired awareness of hypoglycemia (IAH) are at elevated risk of severe, potentially hazardous, hypoglycemia and would benefit from a device alerting to hypoglycemia. Heart rate variability (HRV) changes with hypoglycemia due to sympathetic activity. Since IAH is associated with suppressed sympathetic activity, we investigated whether hypoglycemia elicits a measurable change in HRV in patients with T1D and IAH. Method: Eligible participants underwent a modified hyperinsulinemic euglycemic hypoglycemic clamp (glucose nadir, 43.1 ± 0.90 mg/dl), while HRV was measured by a VitalConnect HealthPatch. Measurements of HRV included Root Mean Square of the Successive Differences (RMSSD) and low to high frequency (LF:HF) ratio. Wilcoxon rank-sum test was used for testing within-subject HRV changes. Results: We included 12 participants (8 female, mean age 57 ± 12 years, mean HbA1c 57 ± 5 mmol/mol (7.4 ± 0.4%)). Symptoms increased from 4.0 (1.5-7.0) at euglycemia to 7.5 (5.0-11.0) during hypoglycemia ( P = .003). In response to hypoglycemia, the LF:HF ratio and RMSSD increased when normalized for data obtained during euglycemia (both P < .01). The LF:HF ratio increased in 6 participants (50%) and declined in one other participant (8%). The RMSSD decreased in 3 (25%) and increased in 4 (33%) participants. In 2 patients, no change in HRV could be detected in response to hypoglycemia. Conclusions: This study reveals that hypoglycemia-induced changes in HRV are retained in the majority of people with T1D and IAH, and that these changes can be detected by a wearable device. Real-time HRV seems usable for detection of hypoglycemia in patients with IAH.

scholarly journals Effect of short-term exposure to particulate air pollution on heart rate variability in normal-weight and obese adults

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Luyi Li ◽  
Dayu Hu ◽  
Wenlou Zhang ◽  
Liyan Cui ◽  
Xu Jia ◽  
...  
Keyword(s):  
Heart Rate ◽  
Air Pollution ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Normal Weight ◽  
High Frequency Power ◽  
Short Term ◽  
Particulate Air Pollution ◽  
Short Term Exposure ◽  
Frequency Power

Abstract Background The adverse effects of particulate air pollution on heart rate variability (HRV) have been reported. However, it remains unclear whether they differ by the weight status as well as between wake and sleep. Methods A repeated-measure study was conducted in 97 young adults in Beijing, China, and they were classified by body mass index (BMI) as normal-weight (BMI, 18.5–24.0 kg/m2) and obese (BMI ≥ 28.0 kg/m2) groups. Personal exposures to fine particulate matter (PM2.5) and black carbon (BC) were measured with portable exposure monitors, and the ambient PM2.5/BC concentrations were obtained from the fixed monitoring sites near the subjects’ residences. HRV and heart rate (HR) were monitored by 24-h Holter electrocardiography. The study period was divided into waking and sleeping hours according to time-activity diaries. Linear mixed-effects models were used to investigate the effects of PM2.5/BC on HRV and HR in both groups during wake and sleep. Results The effects of short-term exposure to PM2.5/BC on HRV were more pronounced among obese participants. In the normal-weight group, the positive association between personal PM2.5/BC exposure and high-frequency power (HF) as well as the ratio of low-frequency power to high-frequency power (LF/HF) was observed during wakefulness. In the obese group, personal PM2.5/BC exposure was negatively associated with HF but positively associated with LF/HF during wakefulness, whereas it was negatively correlated to total power and standard deviation of all NN intervals (SDNN) during sleep. An interquartile range (IQR) increase in BC at 2-h moving average was associated with 37.64% (95% confidence interval [CI]: 25.03, 51.51%) increases in LF/HF during wakefulness and associated with 6.28% (95% CI: − 17.26, 6.15%) decreases in SDNN during sleep in obese individuals, and the interaction terms between BC and obesity in LF/HF and SDNN were both statistically significant (p <  0.05). The results also suggested that the effects of PM2.5/BC exposure on several HRV indices and HR differed in magnitude or direction between wake and sleep. Conclusions Short-term exposure to PM2.5/BC is associated with HRV and HR, especially in obese individuals. The circadian rhythm of HRV should be considered in future studies when HRV is applied. Graphical abstract

Heart rate variability and baroreflex sensitivity are reduced in chronically undernourished, but otherwise healthy, human subjects

2003 ◽  
Vol 104 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Mario VAZ ◽  
A.V. BHARATHI ◽  
S. SUCHARITA ◽  
D. NAZARETH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Human Subjects ◽  
Normal Weight ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Human ◽  
Frequency Power

Alterations in autonomic nerve activity in subjects in a chronically undernourished state have been proposed, but have been inadequately documented. The present study evaluated heart rate and systolic blood pressure variability in the frequency domain in two underweight groups, one of which was undernourished and recruited from the lower socio-economic strata [underweight, undernourished (UW/UN); n = 15], while the other was from a high class of socio-economic background [underweight, well nourished (UW/WN); n = 17], as well as in normal-weight controls [normal weight, well nourished (NW/WN); n = 27]. Baroreflex sensitivity, which is a determinant of heart rate variability, was also assessed. The data indicate that total power (0–0.4Hz), low-frequency power (0.04–0.15Hz) and high-frequency power (0.15–0.4Hz) of RR interval variability were significantly lower in the UW/UN subjects (P<0.05) than in the NW/WN controls when expressed in absolute units, but not when the low- and high-frequency components were normalized for total power. Baroreflex sensitivity was similarly lower in the UW/UN group (P<0.05). Heart rate variability parameters in the UW/WN group were generally between those of the UW/UN and NW/WN groups, but were not statistically different from either. The mechanisms that contribute to the observed differences between undernourished and normal-weight groups, and the implications of these differences, remain to be elucidated.

scholarly journals The Influence ofNrf2on Cardiac Responses to Environmental Stressors

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
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.

scholarly journals Effect of Acupuncture on Heart Rate Variability: A Systematic Review

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
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.

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 use of heart rate turbulence and heart rate variability in the assessment of autonomic regulation and circadian rhythm in patients with systemic lupus erythematosus without apparent heart disease

Lupus ◽  
2017 ◽  
Vol 27 (3) ◽  
pp. 436-444 ◽  
Author(s):  
A R Poliwczak ◽  
E Waszczykowska ◽  
B Dziankowska-Bartkowiak ◽  
M Koziróg ◽  
K Dworniak
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Lupus Erythematosus ◽  
High Frequency ◽  
Autonomic Function ◽  
Disease Duration ◽  
Control Group ◽  
Systemic Lupus ◽  
Heart Rate Turbulence

Background Systemic lupus erythematosus is a progressive autoimmune disease. There are reports suggesting that patients even without overt signs of cardiovascular complications have impaired autonomic function. The aim of this study was to assess autonomic function using heart rate turbulence and heart rate variability parameters indicated in 24-hour ECG Holter monitoring. Methods Twenty-six women with systemic lupus erythematosus and 30 healthy women were included. Twenty-four hour ambulatory ECG-Holter was performed in home conditions. The basic parameters of heart rate turbulence and heart rate variability were calculated. The analyses were performed for the entire day and separately for daytime activity and night time rest. Results There were no statistically significant differences in the basic anthropometric parameters. The mean duration of disease was 11.52 ± 7.42. There was a statistically significant higher turbulence onset (To) value in patients with systemic lupus erythematosus, median To = –0.17% (minimum –1.47, maximum 3.0) versus To = –1.36% (minimum –4.53, maximum –0.41), P < 0.001. There were no such differences for turbulence slope (Ts). In the 24-hour analysis almost all heart rate variability parameters were significantly lower in the systemic lupus erythematosus group than in the healthy controls, including SDANN and r-MSSD and p50NN. Concerning the morning activity and night resting periods, the results were similar as for the whole day. In the control group, higher values in morning activity were noted for parameters that characterise sympathetic activity, especially SDANN, and were significantly lower for parasympathetic parameters, including r-MSSD and p50NN, which prevailed at night. There were no statistically significant changes for systemic lupus erythematosus patients for p50NN and low and very low frequency. There was a positive correlation between disease duration and SDNN, R = 0.417; P < 0.05 and SDANN, R = 0.464; P < 0.05, a negative correlation between low/high frequency ratio and r-MSSD, R = –0.454; P < 0.05; p50NN, R = –0.435; P < 0.05 and high frequency, R = –0.478; P < 0.05. In contrast, there was no statistically significant correlation between heart rate turbulence and other variables evaluated, including disease duration and the type of autoantibodies. Conclusion: Our study confirms the presence of autonomic disorders with respect to both heart rate variability and heart rate turbulence parameters and the presence of diurnal disturbances of sympathetic–parasympathetic balance. Further studies are required.

Effect of fingolimod on cardiac autonomic regulation in patients with multiple sclerosis

2015 ◽  
Vol 22 (8) ◽  
pp. 1080-1085 ◽  
Author(s):  
Sakari Simula ◽  
Tomi Laitinen ◽  
Tiina M Laitinen ◽  
Tuula Tarkiainen ◽  
Päivi Hartikainen ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Frequency Ratio ◽  
Low Frequency ◽  
Autonomic Regulation ◽  
Rr Interval ◽  
Cardiac Autonomic Regulation ◽  
Multiple Sclerosis Patients

Background: Fingolimod modulates sphingosine-1-phosphate receptors that are also found in cardiovascular tissue. Objective: To investigate the effects of fingolimod on cardiac autonomic regulation prospectively. Methods: Twenty-seven relapsing–remitting multiple sclerosis patients underwent 24-hour electrocardiogram recording before, at the first day of fingolimod treatment (1d) and after three months of continuous dosing (3mo). The time interval between two consecutive R-peaks (RR-interval) was measured. Cardiac autonomic regulation was assessed by the various parameters of heart rate variability. Parasympathetic stimulation prolongs the RR-interval and increases heart rate variability while the effects of sympathetic stimulation are mainly the opposite. The low frequency/high frequency ratio reflects sympathovagal balance. Results: From baseline to 1d, a prolongation of the RR-interval ( P<0.001), an increase in the values of various heart rate variability parameters ( P<0.05 to P<0.001) and a decrease in the low frequency/high frequency ratio ( P<0.05) were demonstrated. At 3mo, although the RR-interval remained longer ( P<0.01), the values of various heart rate variability parameters were lower ( P<0.01 to P<0.001) as compared to baseline. At 3mo, the low frequency/high frequency ratio ( P<0.05) was higher in men than in women although no such difference was found at baseline or at 1d. Conclusions: After an initial increase in parasympathetic regulation, continuous fingolimod dosing shifts cardiac autonomic regulation towards sympathetic predominance, especially in men. Careful follow-up of fingolimod-treated relapsing–remitting multiple sclerosis patients is warranted as sympathetic predominance associates generally with impaired outcome. ClinicalTrials.cov: NCT01704183

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