Blunted Cardiac Autonomic Responsiveness to Hypoxemic Stress in Healthy Older Adults

2003 ◽  
Vol 28 (4) ◽  
pp. 518-535 ◽  
Author(s):  
S. Deborah Lucy ◽  
John M. Kowalchuk ◽  
Richard L. Hughson ◽  
Donald H. Paterson ◽  
David A. Cunningham
Keyword(s):  
Older Adults ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Spectral Power ◽  
Coarse Graining ◽  
Key Words Heart ◽  
Key Words Heart Rate ◽  
Age Related ◽  
End Tidal

Supine resting cardiac dynamics and responses to steady-state hypoxemia were investigated in six healthy older (59-72 yrs) adults using coarse-graining spectral analysis of heart rate variability (HRV) and were compared to six young (22-29 yrs) adults studied previously (Lucy et al<normal + trebuchet ms char,12 pt char, black char, condensed by 0.05 pt char>.,</normal + trebuchet ms char,12 pt char, black char, condensed by 0.05 pt char> 2000). End-tidal carbon dioxide pressure (PETCO2) was clamped at 1-2 mmHg above the usual resting value for 11 min of euoxia (PETO2100 mmHg), followed by 22 min of hypoxia (PETO2 55 mmHg). During euoxia, vagally mediated harmonic and fractal power of HRV of older adults was minimal. Hypoxia induced an increase in ventilation, p < 0.01, and heart rate, p < 0.05. The heart rate increase (mean ± SE) of 0.23 ± 0.08 beats•min−1 per 1% decrease in arterial O2 saturation was 25% of that demonstrated previously by young subjects, p < 0.001. In older adults, HRV spectral power remained unchanged during hypoxia, providing further evidence of an age-related blunting of cardiac autonomic function. Key words: heart rate variability, coarse-graining spectral analysis, cardiac vagal control, acute isocapnic hypoxia, dynamic end-tidal forcing (DEF) technique

Features of changes in heart rate variability indices in driving school cadets with different levels of preparedness

2021 ◽  
Author(s):  
S.E. Bebinov ◽  
O.N. Krivoshchekova ◽  
A.V. Nechaev
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Simulator Training ◽  
Training Level ◽  
Driver Training ◽  
Traffic Conditions ◽  
Key Words Heart ◽  
Key Words Heart Rate ◽  
Regulatory Systems ◽  
Different Levels

The research was carried out on two independent experimental groups of boys and girls. The first was observed in traffic conditions, the second during the period of auto-simulator training. The HRV indices were determined: HR - heart rate, IN - index of tension of regulatory systems, AMo - amplitude of the mode, LF/HF - index of vagosympathetic interaction. A pronounced sympathetic reaction of more prepared cadets to the training load with the subsequent restoration of the studied characteristics was revealed. Key words: heart rate variability, autonomic regulation, vagosympathetic interaction, driver training, level of preparedness.

Assessment of the adaptive state of students based on the analysis of heart rate variability indicators

2021 ◽  
Author(s):  
N.V. Mishchenko ◽  
S.V. Lyalyakin ◽  
L.A. Shirkin ◽  
E.S. Knyazeva ◽  
T.A. Trifonova
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Key Words ◽  
The State ◽  
Key Words Heart ◽  
Key Words Heart Rate ◽  
Regulatory Systems ◽  
Young Students

In the course of the study, the adaptive state of VlSU students was assessed by temporal, spectral, cardiointervalographic and integral indicators of heart rate variability. The characteristic of the state of the regulatory systems of students is given. The obtained results can serve as a certain addition to the understanding of the peculiarities of the process of adaptation of young students in the conditions of studying at higher school. Key words: heart rate variability (HRV), students, adaptation, regulatory systems, sympathetic and parasympathetic influence.

The Effects of Anxiety on Motor Performance: A Test of the Conscious Processing Hypothesis

2005 ◽  
Vol 27 (2) ◽  
pp. 212-225 ◽  
Author(s):  
Richard Mullen ◽  
Lew Hardy ◽  
Andrew Tattersall
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Motor Performance ◽  
Spectral Power ◽  
High Anxiety ◽  
Performance Effects ◽  
Conscious Processing ◽  
Task Irrelevant ◽  
Anxiety Condition

The aim of this study was to examine the conscious processing hypothesis as an explanation of the anxiety/performance relationship. The study was designed to identify conscious processing performance effects while controlling for an alternative attentional threshold explanation identified in previous research. Participants completed 60 golf putts. They completed 3 blocks of 10 putts in single task, task-relevant shadowing, and task-irrelevant tone-counting conditions. Each set of 3 × 10 putts was completed in low and high anxiety conditions. Anxiety was elevated using an instructional set. Self-reported effort and spectral analysis of heart rate variability were used to examine the patterning of effort across the different putting conditions. Findings indicated that performance was impaired in the high anxiety shadowing and tone-counting conditions, supporting an attentional threshold interpretation. Spectral analysis of heart rate variability indicated that potential compensatory increases in spectral power in the high frequency band associated with dual-task putting in the low anxiety condition were absent in the high anxiety tone-counting and shadowing putting conditions, partially reflecting the performance findings. No effects were found for self-reported effort. Taken together, the performance and heart rate variability results support an attentional interpretation of the anxiety/motor performance relationship.

Sympathetic and parasympathetic indicators of heart rate control at altitude studied by spectral analysis

1994 ◽  
Vol 77 (6) ◽  
pp. 2537-2542 ◽  
Author(s):  
R. L. Hughson ◽  
Y. Yamamoto ◽  
R. E. McCullough ◽  
J. R. Sutton ◽  
J. T. Reeves
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Placebo Group ◽  
High Frequency ◽  
Spectral Power ◽  
Adaptive Responses ◽  
Propranolol Group ◽  
Total Spectral Power ◽  
Receptor Number

The adaptive responses of the cardiovascular system to altitude appear to be dominated by increased sympathetic neural activity. We investigated the combined roles of the sympathetic and parasympathetic nervous systems (SNS and PNS, respectively) in the early (days 4–5) and subsequent (days 11–12) phases of acclimatization on Pike's Peak, CO (4,300 m), by spectral analysis of heart rate variability. Male subjects were randomly assigned to groups receiving oral propranolol (240 mg/day; n = 6) or a matched placebo (n = 3). On ascent to altitude, the high-frequency, fractal, and total spectral powers were reduced in the placebo group during days 4–5 and 11–12. At altitude during days 4–5, all three placebo group subjects increased SNS and decreased PNS activities compared with at sea level, and during days 11–12 SNS decreased and PNS increased compared with days 4–5. Relative to the placebo group, propranolol caused lengthening of the R-R interval; increases in high-frequency power, total spectral power, and the PNS indicator; and a decrease in the SNS indicator. Total spectral power tended to decrease at altitude, but there were no effects of altitude on PNS and SNS indicators in the propranolol group. The data from the placebo and propranolol groups suggest that both the PNS and SNS are involved in the elevated heart rate during the early phase of altitude acclimatization. Changes in heart rate variability during days 11–12 at altitude must be considered in light of the possible reductions in sympathetic receptor number noted in previous studies.

scholarly journals Analysis of indicators of short recording of heart rate variability in comorbid patients with non-communicable diseases

2021 ◽  
Vol 25 (2(98)) ◽  
pp. 82-88
Author(s):  
G. Nevoit ◽  
M. Potiazhenko
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Functional State ◽  
Spectral Power ◽  
Modern Science ◽  
Communicable Diseases ◽  
The Body ◽  
Non Communicable Diseases ◽  
Comprehensive Examination

The issues of clinical significance and possibilities of assessing the indicators of variation pulsometry measurement and spectral analysis of a short recording of heart rate variability are highlighted in the article. This is necessary as an objective justification for the subsequent assessment of the functional state of the body and a comprehensive examination of comorbid patients for non-communicable diseases.The aim of the study was to assess the clinical and diagnostic value of a short recording of heart rate variability in comorbid patients with non-communicable diseases in order to increase the effectiveness of measures for their prevention and treatment in Ukraine by improving their diagnosis and prevention through the introduction of modern science-intensive technologies into medical practice.Material and methods. 174 comorbid patients with non-communicable diseases were examined by registering a short record of variability on the hardware-soft-ware complex Poly-Spectrum (Neurosoft, Russia) and the analysis of the results was done. The patients were divided into three groups depending on the degree of comorbidity.Results. Significant differences in spectral analysis and variation pulsometry measurements were established in patients with non-communicable diseases, depending on the degree of comorbidity.Conclusions. The expediency of using the method of short recording of heart rate variability in a comprehensive examination of comorbid patients has been established. The indicator of the total spectral power of the heart rate can be recommended for use as an additional independent predictor of the severity of comorbid pathology and assessment of the functional state.

Heart rate variability and fractal dimension during orthostatic challenges

1993 ◽  
Vol 75 (6) ◽  
pp. 2602-2612 ◽  
Author(s):  
G. C. Butler ◽  
Y. Yamamoto ◽  
H. C. Xing ◽  
D. R. Northey ◽  
R. L. Hughson
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Fractal Dimension ◽  
Cardiovascular System ◽  
Lower Body Negative Pressure ◽  
Broad Band ◽  
Coarse Graining ◽  
Noise Spectrum ◽  
Four Levels

Heart rate variability (HRV) spectral analysis has been used as a tool for short-term assessment of parasympathetic (PNS) and sympathetic nervous system (SNS) control of heart rate. However, it has been suggested that the PNS and SNS indicators are superimposed on a broad-band noise spectrum in which the power spectral densities are inversely proportional to their frequency (1/f beta). In this study, we have used coarse-graining spectral analysis to extract the harmonic components for calculation of PNS and SNS indicators and to obtain the slope (beta) of the 1/f beta component to estimate fractal dimension (DF) of a trail of HRV. DF was regarded as an indicator of cardiovascular system complexity. Ten healthy young subjects (6 women and 4 men) were studied in supine rest and with sequential applications of four levels of lower body negative pressure (LBNP; -10, -20, -30, and -50 mmHg) and head-up tilt (HUT; 10, 20, 30, and 70 degrees). In the 20 tests, there were six occurrences of presyncopal symptoms that required the test to be terminated before the planned end point. At low levels of LBNP or HUT, arterial pulse pressure (PP) was not changed from rest, and calculated DF was very high (beta approximately 1.00). At the higher levels of LBNP and HUT, PP decreased. Coincident with this reduction in PP, PNS activity decreased, SNS activity increased, and DF was reduced, each with a significant linear relationship to the change in PP (PNS: r = 0.56; SNS: r = 0.57; DF: r = 0.70, P < 0.01). Each occurrence of presyncope was associated a low PNS indicator as well as DF < 2.50 (beta > or = 1.80). These data indicate that the cardiovascular system is operating at a reduced level of complexity and further suggest that reduced complexity might not be compatible with cardiovascular homeostasis.

scholarly journals Even slight movements disturb analysis of cardiovascular dynamics

1999 ◽  
Vol 277 (1) ◽  
pp. H261-H267 ◽  
Author(s):  
Jacques-Olivier Fortrat ◽  
Cédric Formet ◽  
Jean Frutoso ◽  
Claude Gharib
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Low Frequency ◽  
Coarse Graining ◽  
Spectral Exponent ◽  
Spontaneous Movements ◽  
Frequency Components ◽  
Fractal Noise

We hypothesized that spontaneous movements (postural adjustments and ideomotion) disturb analysis of heart rate and blood pressure variability and could explain the discrepancy between studies. We measured R-R intervals and systolic blood pressure in nine healthy sitting subjects during three protocols: 1) no movement allowed, 2) movements allowed but not standing, 3) movements and standing allowed. Heart rate and blood pressure were not altered by movements. Movements with or without standing produced a twofold or greater increase of the overall variability of R-R intervals and of the low-frequency components of spectral analysis of heart rate variability. The spectral exponent β of heart rate variability (1.123 at rest) was changed by movements (1.364), and the percentage of fractal noise (79% at rest) was increased by standing (91%, coarse-graining spectral analysis). Spontaneous movements could induce a plateau in the correlation dimensions of heart rate variability, but they changed its nonlinear predictability. We suggest that future studies on short-term cardiovascular variability should control spontaneous movements.

Frequency characteristics of long-term heart rate variability during constant-routine protocol

2003 ◽  
Vol 285 (1) ◽  
pp. R171-R176 ◽  
Author(s):  
Naoko Aoyagi ◽  
Kyoko Ohashi ◽  
Yoshiharu Yamamoto
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Core Body Temperature ◽  
Coarse Graining ◽  
Daily Routine ◽  
Crossover Frequency ◽  
Behavioral Factors

The effects of such behavioral factors as physical activity, food intake, and circadian rhythm on long-term heart rate variability (HRV) in humans remain poorly understood. We therefore studied their effects on HRV using a constant-routine protocol that included simultaneous core body temperature (CBT) correction. Seven healthy subjects completed the constant-routine and daily-routine protocols, during which HRV and CBT were continuously monitored. During the constant routine, subjects were kept awake for 27 h in a semirecumbent posture with minimal physical activity; small isocaloric meals were provided every 2 h. During the daily routine, subjects carried on their lives normally. Data were analyzed using generic spectral analysis based on a fast Fourier transform; coarse-graining spectral analysis was also used to eliminate periodicity due to the regular meals for raw HRV and for the CBT-corrected HRV without circadian and/or low-frequency ultradian components. The results showed that 1) the power spectra of HRV in the constant routine and daily routine had similar power-law scalings at frequencies above ∼10-3.5 Hz, while 2) below that crossover frequency, HRV was smaller in the constant routine than in the daily routine, with the difference becoming significant ( P < 0.05) at <10-4 Hz, 3) coarse-graining spectral analysis eliminated diet-induced peaks in generic spectral analysis-based HRV spectra during the constant routine and emphasized the crossover at ∼10-3.5 Hz, and 4) CBT correction did not alter the results. Below a frequency of ∼10-3.5 Hz (a period >1 h), HRV is strongly influenced by behavioral factors; above that crossover frequency, HRV is behavior independent, possibly reflecting an intrinsic regulatory system.

Validation of a heart-rate monitor for measuring a stress response in dairy cows

1994 ◽  
Vol 74 (3) ◽  
pp. 465-474 ◽  
Author(s):  
Hans Hopster ◽  
Harry J. Blokhuis
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Dairy Cows ◽  
Pulse Generator ◽  
Farm Animals ◽  
Relevant Parameter ◽  
Heart Rate Monitor ◽  
Key Words Heart ◽  
Key Words Heart Rate ◽  
Highly Correlated

In three experiments, a commercial non-invasive heart-rate monitor, Polar® Sport Tester (PST), was validated for use with dairy cows. First, 10 monitors were tested using a pulse generator, which produced pulses at levels between 30 and 240 bpm. PST values and generated beats were highly correlated (r = 0.97) but with varying delay (5–55 s), depending on pulse-rate level.In a second experiment, 10 dairy cows were quietly standing or exercising on a treadmill while their heart rates were recorded by direct-wire electrocardiograph (ECG) as well as the PST. Correlations between ECG and PST values during standing (0.88) and exercising (0.72) were significant and differed between cows. During standing, inter-beat interval and PST standard deviations were significantly correlated (Rsp = 0.76), as were their coefficients of variation (Rsp = 0.89).The third experiment showed that the heart rate of 10 dairy cows increased rapidly immediately after an individual was isolated from the herd. Cows showed no obvious signs of being hampered by the equipment during the 1-h trials.Change in heart rate may be a relevant parameter for studying an animal's response to a stressor. As heart-rate variability is thought to serve as an important mechanism for adaptability in humans, this aspect needs further attention in farm animals. The PST is suitable for measuring both heart rate and heart-rate variability in dairy cows. Key words: Heart rate, dairy cows, stress, treadmill

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