Cardiocirculatory coupling during sinusoidal baroreceptor stimulation and fixed-frequency breathing

2000 ◽  
Vol 99 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Cornelius KEYL ◽  
Martin DAMBACHER ◽  
Annette SCHNEIDER ◽  
Claudio PASSINO ◽  
Ulrike WEGENHORST ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Function Analysis ◽  
Time Lag ◽  
Fixed Frequency ◽  
Sinus Arrhythmia ◽  
Rr Interval ◽  
Transfer Function Analysis ◽  
Baroreceptor Stimulation

The question of whether respiratory sinus arrhythmia (RSA) originates mainly from a central coupling between respiration and heart rate, or from baroreflex mechanisms, is a subject of controversy. If there is a major contribution of baroreflexes to RSA, cardiocirculatory coupling during breathing and during cyclic baroreflex stimulation should show similarities. We applied a sinusoidal stimulus to the carotid baroreceptors and generated heart rate fluctuations of the same magnitude as RSA with a frequency similar to, but different from, the breathing frequency (0.2 Hz, compared with 0.25 Hz), and at 0.1 Hz, in 17 supine healthy subjects (age 28–39 years). The data were analysed using discrete Fourier-transform and transfer function analysis. Respiratory fluctuations in systolic blood pressure preceded RSA with a time lag equal to that between baroreceptor stimulation and oscillations in RR interval (0.62±0.18 s compared with 0.57±0.28 s at 0.2 Hz neck suction). The response of systolic blood pressure to neck suction at 0.2 Hz was 5 times less than the respiratory blood pressure fluctuations. Neck suction at 0.1 Hz largely increased fluctuations in blood pressure and RR interval, whereas the spontaneous phase relationship between blood pressure and RR interval remained unchanged. Our results are not consistent with the hypothesis that the origin of RSA is predominantly a central phenomenon which secondarily generates fluctuations in blood pressure, but suggest that, under the condition of fixed-frequency breathing at 0.25 Hz, baroreflex mechanisms contribute to respiratory fluctuations in RR interval.

Effect of head-down-tilt bed rest and hypovolemia on dynamic regulation of heart rate and blood pressure

2000 ◽  
Vol 279 (6) ◽  
pp. R2189-R2199 ◽  
Author(s):  
Ken-Ichi Iwasaki ◽  
Rong Zhang ◽  
Julie H. Zuckerman ◽  
James A. Pawelczyk ◽  
Benjamin D. Levine
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Transfer Function ◽  
Stroke Volume ◽  
Plasma Volume ◽  
High Frequency ◽  
Function Analysis ◽  
Bed Rest ◽  
Baroreflex Control ◽  
Transfer Function Analysis

Adaptation to head-down-tilt bed rest leads to an apparent abnormality of baroreflex regulation of cardiac period. We hypothesized that this “deconditioning response” could primarily be a result of hypovolemia, rather than a unique adaptation of the autonomic nervous system to bed rest. To test this hypothesis, nine healthy subjects underwent 2 wk of −6° head-down bed rest. One year later, five of these same subjects underwent acute hypovolemia with furosemide to produce the same reductions in plasma volume observed after bed rest. We took advantage of power spectral and transfer function analysis to examine the dynamic relationship between blood pressure (BP) and R-R interval. We found that 1) there were no significant differences between these two interventions with respect to changes in numerous cardiovascular indices, including cardiac filling pressures, arterial pressure, cardiac output, or stroke volume; 2) normalized high-frequency (0.15–0.25 Hz) power of R-R interval variability decreased significantly after both conditions, consistent with similar degrees of vagal withdrawal; 3) transfer function gain (BP to R-R interval), used as an index of arterial-cardiac baroreflex sensitivity, decreased significantly to a similar extent after both conditions in the high-frequency range; the gain also decreased similarly when expressed as BP to heart rate × stroke volume, which provides an index of the ability of the baroreflex to alter BP by modifying systemic flow; and 4) however, the low-frequency (0.05–0.15 Hz) power of systolic BP variability decreased after bed rest (−22%) compared with an increase (+155%) after acute hypovolemia, suggesting a differential response for the regulation of vascular resistance (interaction, P < 0.05). The similarity of changes in the reflex control of the circulation under both conditions is consistent with the hypothesis that reductions in plasma volume may be largely responsible for the observed changes in cardiac baroreflex control after bed rest. However, changes in vasomotor function associated with these two conditions may be different and may suggest a cardiovascular remodeling after bed rest.

scholarly journals Time-Frequency Analysis of Cardiovascular and Cardiorespiratory Interactions During Orthostatic Stress by Extended Partial Directed Coherence

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 468 ◽  
Author(s):  
Sonia Charleston-Villalobos ◽  
Sina Reulecke ◽  
Andreas Voss ◽  
Mahmood R. Azimi-Sadjadi ◽  
Ramón González-Camarena ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Information Flow ◽  
Orthostatic Intolerance ◽  
Linear Method ◽  
Orthostatic Stress ◽  
Partial Directed Coherence ◽  
Sinus Arrhythmia ◽  
Time Frequency

In this study, the linear method of extended partial directed coherence (ePDC) was applied to establish the temporal dynamic behavior of cardiovascular and cardiorespiratory interactions during orthostatic stress at a 70° head-up tilt (HUT) test on young age-matched healthy subjects and patients with orthostatic intolerance (OI), both male and female. Twenty 5-min windows were used to analyze the minute-wise progression of interactions from 5 min in a supine position (baseline, BL) until 18 min of the orthostatic phase (OP) without including pre-syncopal phases. Gender differences in controls were present in cardiorespiratory interactions during OP without compromised autonomic regulation. However in patients, analysis by ePDC revealed considerable dynamic alterations within cardiovascular and cardiorespiratory interactions over the temporal course during the HUT test. Considering the young female patients with OI, the information flow from heart rate to systolic blood pressure (mechanical modulation) was already increased before the tilt-up, the information flow from systolic blood pressure to heart rate (neural baroreflex) increased during OP, while the information flow from respiration to heart rate (respiratory sinus arrhythmia) decreased during the complete HUT test. Findings revealed impaired cardiovascular interactions in patients with orthostatic intolerance and confirmed the usefulness of ePDC for causality analysis.

Smoking impairs baroreflex sensitivity in humans

1997 ◽  
Vol 273 (3) ◽  
pp. H1555-H1560 ◽  
Author(s):  
G. Mancia ◽  
A. Groppelli ◽  
M. Di Rienzo ◽  
P. Castiglioni ◽  
G. Parati
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Pulse Interval ◽  
Average Systolic Blood Pressure ◽  
Carotid Baroreceptor ◽  
Baroreceptor Stimulation ◽  
Finger Blood Pressure ◽  
Carotid Baroreceptor Stimulation

In 10 healthy smokers, finger blood pressure was recorded continuously for 1 h in a supine control condition and for 1 h while smoking four cigarettes, one every 15 min. Smoking increased average systolic blood pressure (+19%, P < 0.01) and its variability and reduced pulse interval (reciprocal of heart rate, -22%, P < 0.01) and its variability. Baroreflex sensitivity, as assessed by the slope of spontaneous hypertension/bradycardia or hypotension/tachycardia sequences and by the alpha-coefficient (squared ratio between pulse interval and systolic blood pressure spectral powers at 0.1 Hz) was significantly decreased (P < 0.01) during smoking, whereas there were no effects of smoking on the reflex changes in pulse interval induced by carotid baroreceptor stimulation through a neck suction device. Sham smoking by a drinking straw had no effects on any of the above parameters. Thus, when assessed in the absence of laboratory maneuvers in daily life conditions, baroreflex sensitivity is markedly impaired by smoking. This impairment may contribute to the smoking-induced increase in blood pressure and heart rate as well as to the concomitant alterations in their variability.

scholarly journals Effect of Suboccipital Release on Pain Perception and Autonomic Reflex Responses to Ischemic and Cold Pain

Pain Medicine ◽  
2020 ◽  
Vol 21 (11) ◽  
pp. 3024-3033
Author(s):  
Kristen Metzler-Wilson ◽  
Abby Vrable ◽  
Andrew Schaub ◽  
Trenton K Schmale ◽  
Benjamin V Rodimel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Pain Perception ◽  
Function Analysis ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Cold Pain ◽  
Arterial Blood ◽  
Transfer Function Analysis

Abstract Objective/Subjects To determine the autonomic effects of suboccipital release (SOR) during experimentally induced pain, 16 healthy subjects (eight women, eight men) experienced ischemic (forearm postexercise muscle ischemia [PEMI]) and cold (cold pressor test [CPT]) pain. Design Beat-to-beat heart rate (electrocardiogram), mean arterial blood pressure (finger photoplethysmography), baroreflex sensitivity (transfer function analysis), and pain perception were measured. SOR or a sham (modified yaw; 30 cycles/min) was performed in minute 2 of pain. Results PEMI increased blood pressure by 23 ± 2 and 20 ± 2 mmHg; no differences occurred between SOR or yaw. PEMI modestly elevated heart rate during ischemia, followed by significant reduction from baseline with SOR (–3 ± 2 bpm) and yaw (−4 ± 2 bpm); no differences were observed between treatments. CPT increased blood pressure (SOR = 11 ± 1, yaw = 9 ± 2 mmHg) and heart rate (SOR = 10 ± 2, yaw = 8 ± 3 bpm) before SOR and yaw. Neither treatment nor sham blunted blood pressure increases (SOR = 25 ± 2, yaw = 22 ± 2 mmHg) during CPT; both decreased heart rate (SOR = −3 ± 2, yaw = −2 ± 2 bpm) from baseline. PEMI and CPT caused increased pain without treatment modulation. Following pain and manual intervention, SOR increased baroreflex sensitivity in the 0.15–0.35 Hz range and decreased R-R interval power spectral density in the 0.03–0.5 Hz range compared with yaw. To probe potential mechanisms and interactions between manual treatment and a prototypic analgesic, oral aspirin (967 mg) was given 60 minutes before testing to reduce prostaglandin synthesis. Aspirin slightly attenuated pain but neither altered cardiovascular changes to PEMI nor interacted with SOR or yaw. Conclusions SOR has the capacity to modulate pain-induced autonomic control and regulation.

scholarly journals Respiratory Sinus Arrhythmia in Children—Predictable or Random?

2021 ◽  
Vol 8 ◽  
Author(s):  
Paulina Lubocka ◽  
Robert Sabiniewicz
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Respiratory Sinus Arrhythmia ◽  
Interval Length ◽  
Healthy Children ◽  
Sinus Arrhythmia ◽  
Rr Intervals ◽  
Rr Interval ◽  
The Difference

Background: Respiratory sinus arrhythmia (RSA) is associated with better health in children.Aim: The study was conducted to analyze the trajectory of RSA in 10-year-olds.Methods: A follow-up study on 120 healthy children (62 boys) aged 10.7 ± 0.5 years consisted of a standard 12-lead electrocardiogram, measurements of height, weight and blood pressure. The protocol was repeated after 3 years. Assessment of RSA based on semi-automatic measurements of RR intervals included: the difference between the longest and shortest RR interval duration (pvRSA), the root mean square of differences between successive RR intervals (RMSSD), the standard deviation of the RR interval length (SDNN) and their equivalents corrected for heart rate (RMSSDc and SDNNc).Results: A the first visit 61.7% of children presented with RSA; 51.7% 3 years later. 23.3% of them had RSA only on the first examination; 13.3% only on the second one. The pvRSA, RMSSD, and SDNN measured in 2019 did not differ significantly from their 2016 equivalents (p &gt; 0.05). The decline in RSA defined by RMSSD was noted in 52.5% of children and in 54.2% when defined by SDNN. The corrected values decreased in 68.3 and 64.2% of the participants for RMSSDc and SDNNc, respectively. The students with RSA at both visits had lower heart rate (p &lt; 0.001) and systolic blood pressure (p = 0.010) compared to those with rhythmic electrocardiograms.Conclusions: RSA in children is changeable, though its measurable indices should be adjusted to heart rate.

Lack of peripheral modulation of cardiovascular central oscillatory autonomic activity during apnea in humans

1997 ◽  
Vol 272 (1) ◽  
pp. H123-H129 ◽  
Author(s):  
C. Passino ◽  
P. Sleight ◽  
F. Valle ◽  
G. Spadacini ◽  
S. Leuzzi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Subjects ◽  
Sinus Arrhythmia ◽  
High Frequency Oscillations ◽  
Baroreceptor Stimulation ◽  
The Mean ◽  
Central Oscillator ◽  
Slow Rhythm ◽  
Normal Respiration

Respiratory sinus arrhythmia (RSA) high-frequency oscillations (HF) and slow fluctuations in heart rate (LF) are thought to result from entrainment of a medullary oscillator, from the baroreflex, or from a combination of both central and baroreflex mechanisms. We sought to distinguish between the alternatives by examining with spectral analysis the behavior of heart rate (R-R interval) and blood pressure in 10 healthy subjects (mean age 27 +/- 1 yr) during apnea, altering the rate of preapnea entrainment stimuli by changing the frequency either of respiration (controlled at 0.1 or 0.25 Hz) or of baroreceptor stimulation by sinusoidal neck suction (0 to -30 mmHg, 0.1 or 0.2 Hz). During apnea the RSA-EF power decreased (from 6.73 +/- 0.15 to 3.67 +/- 0.10 In ms2: P < 0.0001), regardless of preapnea conditions, whereas LF power was reduced only if preceded by 0.1-Hz respiration or neck suction [from 8.71 +/- 0.18 to 6.52 +/- 0.11 In ms2 (P < 0.001) and from 8.31 +/- 0.23 to 6.90 +/- 0.38 In ms2 (P < 0.01), respectively]. The LF frequency seen in the R-R interval during apnea was slower than the spontaneous LF during 0.25-Hz breathing (0.082 +/- 0.01 vs. 0.112 +/- 0.001 Hz, P < 0.001), but the maneuvers during preapnea had no influence on the observed frequency or other characteristics of the slow oscillations during apnea. Moreover, we found no evidence of a progressive decrease in the power of the oscillation during apnea. The same behavior was observed on the mean blood pressure signal. In conclusion, a slow rhythm is present during apnea. In healthy subjects at rest the characteristics of this oscillation indicate that it could be generated by a central oscillator this may thus contribute to the origin of LF present during normal respiration, in addition to the baroreflex.

Transfer function analysis of heart rate variability in response to water intake: correlation with gastric myoelectrical activity

2004 ◽  
Vol 96 (6) ◽  
pp. 2226-2230 ◽  
Author(s):  
C. L. Chen ◽  
H. H. Lin ◽  
William C. Orr ◽  
Cheryl C. H. Yang ◽  
Terry B. J. Kuo
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Transfer Function ◽  
Water Intake ◽  
Function Analysis ◽  
Gastric Myoelectrical Activity ◽  
Myoelectrical Activity ◽  
Sinus Arrhythmia ◽  
Transfer Function Analysis ◽  
Before And After

We utilized transfer function analysis of heart rate variability (HRV) and respiration to investigate the effect of water intake on gastric myoelectrical activity and its relationship to vagal activity. The electrogastrography (EGG) and HRV were recorded simultaneously before and after drinking 500 ml of water in 10 healthy subjects. We observed good linearity between lung volumes and HRV signals at a ventilatory rate between 0.2 and 0.4 Hz before and after water intake. The EGG power of 3 cycles/min increased remarkably after the water intake. We found that there was a significant increase in the magnitude of the respiration-HRV transfer function after water intake ( P < 0.05). The EGG 3 cycles/min power was positively correlated with the transfer magnitude throughout the study ( r = 0.54, P = 0.01). These results confirm that transfer function analysis of HRV sensitively identifies subtle changes in the respiratory sinus arrhythmia that occurs with water intake. The present findings suggest that transfer function analysis of HRV and respiration after water intake can be used to evaluate vagal nervous activity in the human gut.

Yoga Practitioners Exhibit Higher Parasympathetic Activity and Baroreflex Sensitivity and Better Adaptability to 40 mm Hg Lower-Body Negative Pressure

2021 ◽  
Author(s):  
Boligarla Anasuya ◽  
K. K. Deepak ◽  
Ashok Jaryal
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Baroreflex Sensitivity ◽  
Lower Body Negative Pressure ◽  
Lower Body ◽  
Rr Interval ◽  
Systolic Blood Pressure Variability ◽  
Yoga Practitioners

Abstract Yoga has been shown to improve autonomic conditioning in humans, as evidenced by the enhancement of parasym-pathetic activity and baroreflex sensitivity. Therefore, we hypothesized that the experience of yoga may result in adaptation to acute hemodynamic changes. To decipher the long-term effects of yoga on cardiovascular variability, yoga practitioners were compared to yoga-naïve subjects during exposure to –40 mm Hg lower-body negative pressure (LBNP). A comparative study was conducted on 40 yoganaïve subjects and 40 yoga practitioners with an average age of 31.08 ± 7.31 years and 29.93 ± 7.57 years, respectively. Heart rate variability, blood pressure variability, baroreflex sensitivity, and correlation between systolic blood pressure and RR interval were evaluated at rest and during LBNP. In yoga practitioners, the heart rate was lower in supine rest (p = 0.011) and during LBNP (p = 0.043); the pNN50 measure of heart rate variability was higher in supine rest (p = 0.011) and during LBNP (p = 0.034). The yoga practitioners’ standard deviation of successive beat-to-beat blood pressure intervals of systolic blood pressure variability was lower in supine rest (p = 0.034) and during LBNP (p = 0.007), with higher sequence baroreflex sensitivity (p = 0.019) and ~ high-frequency baroreflex sensitivity. Mean systolic blood pressure and RR interval were inversely correlated in the yoga group (r = –0.317, p = 0.049). The yoga practitioners exhibited higher parasympathetic activity and baroreflex sensitivity with lower systolic blood pressure variability, indicating better adaptability to LBNP compared to the yoga-naïve group. Our findings indicate that the yoga module was helpful in conditions of hypovolemia in healthy subjects; it is proposed to be beneficial in clinical conditions associated with sympathetic dominance, impaired barore-flex sensitivity, and orthostatic intolerance.

scholarly journals Information Domain Analysis of Respiratory Sinus Arrhythmia Mechanisms

2018 ◽  
pp. S611-S618 ◽  
Author(s):  
J. KROHOVA ◽  
B. CZIPPELOVA ◽  
Z. TURIANIKOVA ◽  
Z. LAZAROVA ◽  
R. WISZT ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Respiratory Sinus Arrhythmia ◽  
Information Transfer ◽  
Human Subjects ◽  
Sinus Arrhythmia ◽  
Cardiorespiratory Control ◽  
Peripheral Mechanism ◽  
Rate Oscillations

Ventilation related heart rate oscillations – respiratory sinus arrhythmia (RSA) – originate in human from several mechanisms. Two most important of them – the central mechanism (direct communication between respiratory and cardiomotor centers), and the peripheral mechanism (ventilation-associated blood pressure changes transferred to heart rate via baroreflex) have been described in previous studies. The major aim of this study was to compare the importance of these mechanisms in the generation of RSA non-invasively during various states by quantifying the strength of the directed interactions between heart rate, systolic blood pressure and respiratory volume signals. Seventy-eight healthy volunteers (32 male, age range: 16.02-25.77 years, median age: 18.57 years) participated in this study. The strength of mutual interconnections among the spontaneous beat-to-beat oscillations of systolic blood pressure (SBP), R-R interval (RR signal) and respiration (volume changes – RESP signal) was quantified during supine rest, orthostatic challenge (head-up tilt, HUT) and cognitive load (mental arithmetics, MA) using bivariate and trivariate measures of cardio-respiratory information transfer to separate baroreflex and nonbaroreflex (central) mechanisms. Our results indicate that both basic mechanisms take part in RSA generation in the intact cardiorespiratory control of human subjects. During orthostatic and mental challenges baroreflex based peripheral mechanism becomes more important.

Individual differences in respiratory sinus arrhythmia

2004 ◽  
Vol 286 (6) ◽  
pp. H2305-H2312 ◽  
Author(s):  
Samia Ben Lamine ◽  
Pascale Calabrese ◽  
Hélène Perrault ◽  
Tuan Pham Dinh ◽  
André Eberhard ◽  
...  
Keyword(s):  
Heart Rate ◽  
Correlation Coefficient ◽  
Respiratory Sinus Arrhythmia ◽  
Spontaneous Breathing ◽  
Function Analysis ◽  
Sinus Arrhythmia ◽  
Interindividual Differences ◽  
Breathing Period ◽  
Transfer Function Analysis ◽  
Instantaneous Heart Rate

To investigate the interindividual differences in respiratory sinus arrhythmia (RSA), recordings of ventilation and electrocardiogram were obtained from 12 healthy subjects for five imposed breathing periods ( TTOT) surrounding each individual's spontaneous breathing period. In addition to the spectral analysis of the R-R interval signal at each breathing period, RSA characteristics were quantified by using a breath-by-breath analysis where a sinusoid was fitted to the changes in instantaneous heart rate in each breath. The amplitude and phase (or delay = phase × TTOT) of this sinusoid were taken as the RSA characteristics for each breath. It was found that for each subject the RSA amplitude- TTOT relationship was linear, whereas the delay- TTOT relationship was parabolic. However, the parameters of these relationships differed between individuals. Linear correlation between the slopes of RSA amplitude versus TTOT regression lines and 1) mean breathing period and 2) mean R-R interval during spontaneous breathing were calculated. Only the correlation coefficient with breathing period was significantly different from zero, indicating that the longer the spontaneous breathing period the lesser the increase in RSA amplitude with increasing breathing period. Similarly, only the correlation coefficient between the curvature of the RSA delay- TTOT parabola and mean breathing period was significantly different from zero; the longer the spontaneous breathing period the larger the curvature of RSA delay. These results suggest that the changes in RSA characteristics induced by changing the breathing period may be explained partly by the spontaneous breathing period of each individual. Furthermore, a transfer function analysis performed on these data suggested interindividual differences in the autonomic modulation of the heart rate.

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