Efficacy of Paced Breathing at the Low-frequency Peak on Heart Rate Variability and Baroreflex Sensitivity

Abstract Introduction Insomnia is a risk factor for hypertension and cardiovascular events, and this association is strongest for sleep-onset insomnia. However, little is known about insomnia on cardiovascular modulation, especially soon after morning awakening, the peak period of time for cardiovascular incidents. This study explored morning cardiovascular function in individuals with sleep-onset insomnia by analysing heart rate variability, blood pressure variability, and baroreflex sensitivity. Methods Sleep structure of the participants (15 good sleepers and 13 individuals with sleep-onset insomnia) was measured by laboratory polysomnography, followed by continuous recordings of the participant’s blood pressure and heart rate for 10 min in the morning. Results When compared to the good sleepers, the insomnia group showed significant reductions in total sleep time, a longer sleep-onset latency, and reduced sleep efficiency. The sleep structure, including durations of sleep stages, numbers of awakenings and arousal index did not differ between the groups. After morning awakening (averaged time: 12.33 ± 10.48 min), the shorter R-R intervals, lower total power, and lower high-frequency power of heart rate variability were observed among individuals with sleep-onset insomnia, compared with good sleepers. Elevated slopes of systolic and diastolic blood pressure, as well as lower baroreflex sensitivity, were also shown in the insomnia group. Indices of sympathetic activity, including low-frequency percentage of heart rate variability or low-frequency power of blood pressure variability, did not differ between the groups. Conclusion Weak vagal activity and blunted baroreflex sensitivity were evident among sleep-onset insomnia. These findings indicate difficulty in initiating sleep, without significant sleep fragmentation, can independently affect morning cardiovascular function. This study provides a possible link between sleep-onset insomnia and risk of cardiovascular events. Support N/A

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Abstract WP301: Noninvasive Beat-to-Beat Assessment of Blood Pressure Variability, Heart Rate Variability and Baroreflex Sensitivity: Which Parameters Best Predict Clinical Outcome After Acute Ischemic Stroke?

Stroke ◽

10.1161/str.47.suppl_1.wp301 ◽

2016 ◽

Vol 47 (suppl_1) ◽

Author(s):

Li Xiong ◽

Ge Tian ◽

Xiangyan Chen ◽

Howan Leung ◽

Thomas Leung ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Ischemic Stroke ◽

Clinical Outcome ◽

Blood Pressure Variability ◽

Baroreflex Sensitivity ◽

Low Frequency ◽

Prognostic Information ◽

Power Spectral

Background and Objectives: Blood pressure variability (BPV), heart rate variability (HRV) and baroreflex sensitivity (BRS) as measures of autonomic function might provide prognostic information in ischemic stroke. We aimed to study noninvasive beat-to-beat assessment of BPV, HRV and BRS in the acute phase of ischemic stroke to determine whether any of them predicted clinical outcome. Methods & Patients: Consecutive ischemic stroke patients within 7 days of symptom onset were enrolled. The frequency components of BPV and HRV by means of power spectral analysis [very low frequency (VLF; < 0.04 Hz); low frequency (LF; 0.04-0.15 Hz); high frequency (HF; 0.15-0.40 Hz); power spectral density (PSD; <0.40 Hz) and LF/HF ratio] were calculated from 10-minute recordings of beat-to-beat blood pressure and heart rate monitoring. The baroreflex slope and baroreflex effectiveness index (BEI) were determined using the sequence method for BRS. Clinical outcome was assessed at 3 months after stroke onset as good or poor by modified Rankin Scale (mRS) (good outcome, mRS ≤ 2). Results: 82 patients were recruited (mean age, 64.6 ± 9.9 years; 89.3% males). Univariate analysis showed that there were significant differences in National Institutes of Health Stroke Scale (NIHSS) at recruitment, VLF diastolic BPV, VLF, HF and PSD systolic BPV, and down ramp BEI between the good and poor outcome groups (all P < 0.05). After adjusting for NIHSS, multivariate logistic regression showed that only HF systolic BPV (OR 1.320; 95% CI, 1.050-1.659; P=0.017) and down BEI (OR 0.950; 95% CI, 0.912-0.990; P=0.014) were independently correlated with poor functional outcome. Conclusions: Beat-to beat highly variable systolic blood pressure and impaired BRS as evaluated by decreased down BEI are associated with an unfavorable functional outcome after acute ischemic stroke. Important prognostic information can be readily obtained from a short period of noninvasive hemodynamics monitoring in the acute stroke patient.

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Effects of respiratory time ratio on heart rate variability and spontaneous baroreflex sensitivity

Journal of Applied Physiology ◽

10.1152/japplphysiol.00163.2013 ◽

2013 ◽

Vol 115 (11) ◽

pp. 1648-1655 ◽

Cited By ~ 20

Author(s):

Yong-Ping Wang ◽

Terry B. J. Kuo ◽

Chun-Ting Lai ◽

Jui-Wen Chu ◽

Cheryl C. H. Yang

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Baroreflex Sensitivity ◽

Sitting Position ◽

Relative Timing ◽

Paced Breathing ◽

Time Ratio ◽

Rate Asymmetry ◽

Heart Rate Asymmetry ◽

Spontaneous Baroreflex

Paced breathing is a frequently performed technique for cardiovascular autonomic studies. The relative timing of inspiration and expiration during paced breathing, however, is not consistent. We, therefore, examined whether indexes of heart rate variability and spontaneous baroreflex sensitivity would be affected by the respiratory time ratio that is set. We studied 14 healthy young adults who controlled their breathing rates to either 0.1 or 0.25 Hz in the supine and sitting positions. Four different inspiratory-to-expiratory time ratios (I/E) (uncontrolled, 1:1, 1:2, and 1:3) were examined for each condition in a randomized order. The results showed spectral indexes of heart rate variability and spontaneous baroreflex sensitivity were not influenced by the I/E that was set during paced breathing under supine and sitting positions. Porta's and Guzik's indexes of heart rate asymmetry were also not different at various I/E during 0.1-Hz breathing, but had larger values at 1:1 during 0.25-Hz breathing, although significant change was found in the sitting position only. At the same time, Porta's and Guzik's indexes obtained during 0.1-Hz breathing were greater than during 0.25-Hz breathing in both positions. The authors suggest that setting the I/E during paced breathing is not necessary when measuring spectral indexes of heart rate variability and spontaneous baroreflex sensitivity under the conditions used in this study. The necessity of paced breathing for the measurement of heart rate asymmetry, however, requires further investigation.

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Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01373.2007 ◽

2008 ◽

Vol 295 (1) ◽

pp. H29-H38 ◽

Cited By ~ 21

Author(s):

Marcus Henze ◽

Davin Hart ◽

Allen Samarel ◽

John Barakat ◽

Laurie Eckert ◽

...

Keyword(s):

Heart Failure ◽

Heart Rate ◽

Heart Rate Variability ◽

Baroreflex Sensitivity ◽

Elevated Plus Maze ◽

Low Frequency ◽

Coronary Artery Ligation ◽

Artery Ligation ◽

Arterial Blood ◽

Plus Maze

Depressed heart rate variability and mood are associated with increased mortality in patients with congestive heart failure (CHF). Here autonomic indexes were assessed 3 and 7 wk after left coronary artery ligation in telemetered rats, after which anxiety-like behaviors were assessed in an elevated plus maze. Low frequency (LF) and high frequency (HF) heart rate variability were reduced in CHF rats 3 wk after infarction (LF, 1.60 ± 0.52 vs. 6.97 ± 0.79 ms2; and HF, 1.53 ± 0.39 vs. 6.20 ± 1.01 ms2; P < 0.01). The number of sequences of interbeat intervals that correlated with arterial pressure was decreased in CHF rats at 3 and 7 wk ( week 3, 26.60 ± 10.85 vs. 59.75 ± 11.4 sequences, P < 0.05; and week 7, 20.80 ± 8.97 vs. 65.38 ± 5.89 sequences, P < 0.01). Sequence gain was attenuated in CHF rats by 7 wk (1.34 ± 0.06 vs. 2.70 ± 0.29 ms/mmHg, P < 0.01). Coherence between interbeat interval and mean arterial blood pressure variability in the LF domain was reduced in CHF rats at 3 (0.12 ± 0.03 vs. 0.26 ± 0.05 k2, P < 0.05) and 7 (0.16 ± 0.02 vs. 0.31 ± 0.05 k2, P < 0.05) wk. CHF rats invariably entered the open arm of the elevated plus maze first and spent more time in the open arms (36.0 ± 15% vs. 4.6 ± 1.9%, P < 0.05). CHF rats also showed a tendency to jump head first off the apparatus, whereas controls did not. Together the data indicate that severe autonomic dysfunction is accompanied by escape-seeking behaviors in rats with verified CHF.

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Sugar-Sweetened Soft Drink Consumption Acutely Decreases Spontaneous Baroreflex Sensitivity and Heart Rate Variability

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00310.2020 ◽

2021 ◽

Author(s):

Christopher L. Chapman ◽

Emma L Reed ◽

Morgan L Worley ◽

Leonard D Pietrafesa ◽

Paul J Kueck ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Baroreflex Sensitivity ◽

Soft Drink ◽

Soft Drinks ◽

Paced Breathing ◽

Soft Drink Consumption ◽

Healthy Humans ◽

Sequence Method

In healthy humans, fructose-sweetened water consumption increases blood pressure variability (BPV) and decreases spontaneous cardiovagal baroreflex sensitivity (cBRS) and heart rate variability (HRV). However, if consuming commercially available soft drinks containing high levels of fructose elicits similar responses is unknown. We hypothesized that high-fructose corn syrup (HFCS) sweetened soft drink consumption increases BPV and decreases cBRS and HRV to a greater extent compared to artificially-sweetened (Diet) and sucrose-sweetened (Sucrose) soft drinks and water. Twelve subjects completed four randomized, double-blinded trials in which they drank 500 mL of water or commercially available soft drinks matched for taste and caffeine content. We continuously measured beat-to-beat blood pressure (photoplethysmography) and R-R interval (ECG) before and 30 minutes after drink consumption during supine rest for 5 minutes during spontaneous and paced breathing. BPV was evaluated using standard deviation (SD), average real variability (ARV), and successive variation (SV) methods for systolic and diastolic blood pressure. cBRS was assessed using the sequence method. HRV was evaluated using the root mean square of successive differences in R-R interval (RMSSD). There were no differences between conditions in the magnitude of change from baseline in SD, ARV, and SV (P≥0.07). There were greater reductions in cBRS during spontaneous breathing in the HFCS (-3±5 ms/mmHg) and Sucrose (-3±5 ms/mmHg) trials compared to Water (+1±5 ms/mmHg, P<0.03). During paced breathing, HFCS evoked greater reductions in RMSSD compared to Water (-26±34 vs. +2±26 ms, P<0.01). These findings suggest that sugar-sweetened soft drink consumption alters cBRS and HRV but not BPV.

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The low frequency power of heart rate variability is neither a measure of cardiac sympathetic tone nor of baroreflex sensitivity

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00361.2014 ◽

2014 ◽

Vol 307 (7) ◽

pp. H1005-H1012 ◽

Cited By ~ 44

Author(s):

Davide Martelli ◽

Alessandro Silvani ◽

Robin M. McAllen ◽

Clive N. May ◽

Rohit Ramchandra

Keyword(s):

Heart Failure ◽

Heart Rate ◽

Heart Rate Variability ◽

Baroreflex Sensitivity ◽

Low Frequency ◽

Sympathetic Tone ◽

Cross Correlation Analysis ◽

Healthy Control ◽

Conscious Sheep ◽

Low Frequency Power

The lack of noninvasive approaches to measure cardiac sympathetic nerve activity (CSNA) has driven the development of indirect estimates such as the low-frequency (LF) power of heart rate variability (HRV). Recently, it has been suggested that LF HRV can be used to estimate the baroreflex modulation of heart period (HP) rather than cardiac sympathetic tone. To test this hypothesis, we measured CSNA, HP, blood pressure (BP), and baroreflex sensitivity (BRS) of HP, estimated with the modified Oxford technique, in conscious sheep with pacing-induced heart failure and in healthy control sheep. We found that CSNA was higher and systolic BP and HP were lower in sheep with heart failure than in control sheep. Cross-correlation analysis showed that in each group, the beat-to-beat changes in HP correlated with those in CSNA and in BP, but LF HRV did not correlate significantly with either CSNA or BRS. However, when control sheep and sheep with heart failure were considered together, CSNA correlated negatively with HP and BRS. There was also a negative correlation between CSNA and BRS in control sheep when considered alone. In conclusion, we demonstrate that in conscious sheep, LF HRV is neither a robust index of CSNA nor of BRS and is outperformed by HP and BRS in tracking CSNA. These results do not support the use of LF HRV as a noninvasive estimate of either CSNA or baroreflex function, but they highlight a link between CSNA and BRS.

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Effects of Low Frequency Electrical Stimulation in Baroreflex Sensitivity and Heart Rate Variability in Rats with Heart Failure

Autonomic Neuroscience ◽

10.1016/j.autneu.2015.07.114 ◽

2015 ◽

Vol 192 ◽

pp. 89

Author(s):

A.L. Rucatti ◽

R.B. Jaenisch ◽

D.D. Rossato ◽

J.H.P. Bonetto ◽

J. Ferreira ◽

...

Keyword(s):

Heart Failure ◽

Heart Rate ◽

Heart Rate Variability ◽

Electrical Stimulation ◽

Baroreflex Sensitivity ◽

Low Frequency

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Cardiac interaction between mother and infant: enhancement of heart rate variability

Scientific Reports ◽

10.1038/s41598-019-56204-5 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Ayami Suga ◽

Maki Uraguchi ◽

Akiko Tange ◽

Hiroki Ishikawa ◽

Hideki Ohira

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Low Frequency ◽

Cardiac Activity ◽

Vagal Activity ◽

Nerve Activity ◽

Paced Breathing ◽

Inner Model ◽

Age Dependent ◽

Vagal Nerve Activity

AbstractThe vagal activity of infants is represented by heart rate variability (HRV) and associated with both growth and socioemotional development. The enhancement of an infant’s vagal tone activity might be beneficial for development. This study explored whether HRV in infants aged 3–8 months can be enhanced by influencing HRV in mothers (40 dyads). The power of the low frequency (LF) component of maternal HRV was facilitated using slow-paced breathing. We investigated whether the change in maternal HRV affected the LF component in infants held by their mothers. In older infants (N = 14, 6–8 months) the LF power showed an increase during maternal paced breathing, whereas a delayed increase occurred after termination of maternal paced breathing in younger infants (N = 16, 3–5 months). These results show that the effects of maternal cardiac activity on the infant’s HRV are age-dependent. This age-dependent reactivity of the infant’s HRV could be due to the development of the inner model in infants which regulates physiological functions, including cardiac activity. This finding might help develop efficient methods for enhancing vagal nerve activity in infants.

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Low-Frequency Spontaneous Fluctuations of R-R Interval and Blood Pressure in Conscious Humans: A Baroreceptor or Central Phenomenon?

Clinical Science ◽

10.1042/cs0870649 ◽

1994 ◽

Vol 87 (6) ◽

pp. 649-654 ◽

Cited By ~ 107

Author(s):

Luciano Bernardi ◽

Stefano Leuzzi ◽

Alberto Radaelli ◽

Claudio Passino ◽

James A. Johnston ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Pressure Fluctuations ◽

Low Frequency ◽

Power Spectral Analysis ◽

Random Order ◽

Reflex Bradycardia ◽

Frequency Peak ◽

Neck Pressure

1. We have tested the hypothesis that the non-respiratory, low-frequency (around 0.1 Hz) fluctuations of heart rate variability are generated by the baroreflexes, but with a delay caused by the slower response of the efferent sympathetic arm, (compared with the vagus), in 11 healthy subjects (mean age ± SD 27 ± 5 years). 2. In random order, at the onset of 20 s of apnoea starting at end expiration, we applied either 600 ms neck suction (−40 mmHg) to the carotid sinus region, or no stimulus (anticipation control), or a loud whistle (alerting control), every 60s, for 30 min. (i.e. 10 of each ‘stimulus’). We recorded neck pressure, blood pressure (Finapres), R-R interval (ECG), infra-red plethysmographic skin blood flow and respiration (impedance). By subtracting the alerting response from the neck suction response we obtained the responses caused purely by baroreceptor stimulation. 3. The initial reflex bradycardia and hypotension was followed by arteriolar vasoconstriction, presumably due to recompensation by the baroreflex, and then by a further reflex bradycardia—producing a decaying oscillation of the R-R interval about the control R-R. The period of this damped oscillation was 0.103 ± 0.024 Hz, similar to the frequency of the low-frequency peak obtained by power spectral analysis of heart rate variability (0.093 ± 0.016 Hz, not significant) at rest. These two values were significantly correlated in individual subjects (r = 0.715, P < 0.025). 4. These findings support the hypothesis that the low-frequency waves of heart rate variability can be generated from baroreceptor sensed blood pressure fluctuations.

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Heart Rate Variability, Emotions, and Music

Journal of Psychophysiology ◽

10.1027/0269-8803/a000021 ◽

2010 ◽

Vol 24 (2) ◽

pp. 112-119 ◽

Cited By ~ 9

Author(s):

F. Riganello ◽

A. Candelieri ◽

M. Quintieri ◽

G. Dolce

Keyword(s):

Data Mining ◽

Heart Rate ◽

Heart Rate Variability ◽

Vegetative State ◽

Low Frequency ◽

Emotional Reactions ◽

Heart Beat ◽

Healthy Controls ◽

Frequency Spectra ◽

Emotional Value

The purpose of the study was to identify significant changes in heart rate variability (an emerging descriptor of emotional conditions; HRV) concomitant to complex auditory stimuli with emotional value (music). In healthy controls, traumatic brain injured (TBI) patients, and subjects in the vegetative state (VS) the heart beat was continuously recorded while the subjects were passively listening to each of four music samples of different authorship. The heart rate (parametric and nonparametric) frequency spectra were computed and the spectra descriptors were processed by data-mining procedures. Data-mining sorted the nu_lf (normalized parameter unit of the spectrum low frequency range) as the significant descriptor by which the healthy controls, TBI patients, and VS subjects’ HRV responses to music could be clustered in classes matching those defined by the controls and TBI patients’ subjective reports. These findings promote the potential for HRV to reflect complex emotional stimuli and suggest that residual emotional reactions continue to occur in VS. HRV descriptors and data-mining appear applicable in brain function research in the absence of consciousness.

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