Power spectral analysis of heart rate variability in traumatic quadriplegic humans

1990 ◽  
Vol 258 (6) ◽  
pp. H1722-H1726 ◽  
Author(s):  
K. Inoue ◽  
S. Miyake ◽  
M. Kumashiro ◽  
H. Ogata ◽  
O. Yoshimura
Keyword(s):  
Spectral Analysis ◽  
High Frequency ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Center Frequency ◽  
Control Group ◽  
Climatic Chamber ◽  
Power Spectral ◽  
Spectral Components ◽  
Chamber Temperature

This study investigated the spontaneous beat-to-beat variabilities in R-R intervals of six traumatic neurologically complete quadriplegic (QP) males and six age-matched healthy males (control) while they were at rest in the supine position in a climatic chamber (temperature 30 degrees C, relative humidity 60%) by means of autoregressive power spectral analysis. As shown by earlier studies, in the control group there were two major spectral components, a high-frequency (HF) component [center frequency 0.30 +/- 0.02 (SE) Hertz equivalent (Hz eq), power 767.5 +/- 384.6 ms2] and a low-frequency (LF) component (0.11 +/- 0.01 Hz eq, 707.5 +/- 198.8 ms2). On the contrary, in the QP group, only the HF component was observed (0.30 +/- 0.02 Hz eq, 421.8 +/- 134.7 ms2). The results suggest that 1) the disappearance of the LF component in the QP subject is presumably caused by the interruption of the spinal pathways linking supraspinal cardiovascular centers with the peripheral sympathetic outflow, and 2) the cervical spinal sympathetic pathways may be instrumental in the genesis of the LF component in humans.

Impact of Changes in Respiratory Frequency and Posture on Power Spectral Analysis of Heart Rate and Systolic Blood Pressure Variability in Normal Subjects and Patients with Heart Failure

1996 ◽  
Vol 91 (1) ◽  
pp. 35-43 ◽  
Author(s):  
John E. Sanderson ◽  
Leata Y. C. Yeung ◽  
Dickens T. K. Yeung ◽  
Richard L. C. Kay ◽  
Brian Tomlinson ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
High Frequency ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Normal Subjects ◽  
Power Spectral ◽  
Patients With Heart Failure

1. Autonomic dysfunction is a major feature of congestive cardiac failure and may have an important role in determining progression and prognosis. The low-frequency/high-frequency ratio derived from power spectral analysis of heart rate variability has been proposed as a non-invasive method to assess sympatho-vagal balance. However, the effects of different respiratory rates or posture are rarely accounted for, but may be relevant in patients with heart failure in whom clinical improvement is accompanied by a fall in respiratory rate and an increased proportion of the day in the upright position. 2. We have assessed the effect of controlled respiration at different rates (10, 15, 20 breaths/min or 0.17, 0.25 and 0.33 Hz), while supine and standing, on power spectral analysis of heart rate and blood pressure variability in 11 patients with heart failure and 10 normal subjects. 3. Heart rate variance and low-frequency power (normalized units) were reduced in patients with heart failure (absent in six). During controlled breathing while supine, the power of the high-frequency component was significantly greater at 10 breaths/min than at 20 breaths/min in patients with heart failure, whether expressed in absolute units (P = 0.005) or percentage of total power (P = 0.03). 4. On standing, controlled breathing in patients with heart failure produced less change in high-frequency power (P = 0.054), but the low-frequency/high-frequency ratio at lower respiratory rates was reduced (P = 0.05). In normal subjects, as expected, respiratory rate had a highly significant effect on high-frequency power. Also, in normal subjects there was the expected increase in heart rate low-frequency power (P = 0.04) moving from supine to standing with an increase in the low-frequency/high-frequency ratio (P = 0.003), while in the patients with heart failure this was absent, reflecting blunted cardiovascular reflexes. 5. Systolic blood pressure low- and high-frequency components and their ratio were significantly affected by respiration (P > 0.03) and change in posture (P > 0.03) in both patients with heart failure and normal subjects, with a significant increase in the low-frequency/high-frequency ratio (P = 0.03) on standing in patients with heart failure, indicating that autonomic modulation of blood pressure is still operating in heart failure. 6. Thus, respiratory rate and changes in posture have a significant effect on measurements derived from spectral analysis of heart rate and blood pressure variability. Studies that use power spectral analysis as a measure of sympatho-vagal balance should control for these variables.

scholarly journals Power spectral analysis of heart rate variability in Bangladeshi healthy male and female

2016 ◽  
Vol 43 (3) ◽  
pp. 146-150
Author(s):  
Qazi Farzana Akhter ◽  
Qazi Shamima Akhter ◽  
Farhana Rahman ◽  
Sybilla Ferdousi ◽  
Susmita Sinha
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
High Frequency ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Autonomic Nerve ◽  
Age Group ◽  
Power Spectral

Heart rate variability (HRV) has been considered as an indicator of autonomic nerve function status. We aimed to find out the reference values of heart rate variability by power spectral analysis in our healthy population of both sex. This cross sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka from the period of July 2012 to June 2013. For this, 180 subjects were selected with the age ranging from 15-60 years. All the study subjects were divided into 3 different groups according to age (Group A: 15-30 years; Group B: 31-45 years; Group C: 46-60 years). Each group contained 60 subjects of which 30 were male and 30 were female. Analysis of HRV parameters were done in Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. Systolic blood pressure, diastolic blood pressure, low frequency normalized unit, low frequency / high frequency ratio were significantly higher in male than female. Again high frequency power, high frequency normalized unit were significantly higher in female than male of same age group. This study concludes that male showed higher cardiac sympathetic activities while female showed higher cardiac parasympathetic activities in different age groups.Bangladesh Med J. 2014 Sep; 43 (3): 146-150

Physiology and Pathophysiology of Heart Rate and Blood Pressure Variability in Humans: Is Power Spectral Analysis Largely An Index of Baroreflex Gain?

1995 ◽  
Vol 88 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Peter Sleight ◽  
Maria Teresa La Rovere ◽  
Andrea Mortara ◽  
Gianni Pinna ◽  
Roberto Maestri ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spectral Analysis ◽  
High Frequency ◽  
Blood Pressure Variability ◽  
Baroreflex Sensitivity ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Autonomic Balance ◽  
Baroreflex Control ◽  
Power Spectral

1. It is often assumed that the power in the low-(around 0.10 Hz) and high-frequency (around 0.25 Hz) bands obtained by power spectral analysis of cardiovascular variables reflects vagal and sympathetic tone respectively. An alternative model attributes the low-frequency band to a resonance in the control system that is produced by the inefficiently slow time constant of the reflex response to beat-to-beat changes in blood pressure effected by the sympathetic (with or without the parasympathetic) arm(s) of the baroreflex (De Boer model). 2. We have applied the De Boer model of circulatory variability to patients with varying baroreflex sensitivity and one normal subject, and have shown that the main differences in spectral power (for both low and high frequency) between and within subjects are caused by changes in the arterial baroreflex gain, particularly for vagal control of heart rate (R—R interval) and left ventricular stroke output. We have computed the power spectrum at rest and during neck suction (to stimulate carotid baroreceptors). We stimulated the baroreceptors at two frequencies (0.1 and 0.2 Hz), which were both distinct from the controlled respiration rate (0.25 Hz), in both normal subjects and heart failure patients with either sensitive or poor baroreflex control. 3. The data broadly confirm the De Boer model. The low-frequency (0.1 Hz) peak in either R—R or blood pressure variability) was spontaneously generated only if the baroreflex control of the autonomic outflow was relatively intact. With a large stimulus to the carotid baroreceptor it was possible to influence the low-frequency R—R but not low-frequency blood pressure variability. This implies that it is too simplistic to use power spectral analysis as a simple measure of autonomic balance its underlying modulation is more complex than generally believed. 4. It may be that power spectral analysis is more a sensitive indicator of baroreflex control, particularly of vagal control, than direct evidence of autonomic balance. of course, there is often a correlation between the gain of the reflex and the autonomic balance of vagus and sympathetic. These considerations may help our understanding of some conditions, such as exercise or heart failure, when the power spectral analysis method fails to identify increased sympathetic discharge; this failure may partly be explained by the decrease in baroreflex sensitivity which occurs in these two conditions.

Hyperinsulinemia produces cardiac vagal withdrawal and nonuniform sympathetic activation in normal subjects

1999 ◽  
Vol 276 (1) ◽  
pp. R178-R183 ◽  
Author(s):  
Philippe Van De Borne ◽  
Martin Hausberg ◽  
Robert P. Hoffman ◽  
Allyn L. Mark ◽  
Erling A. Anderson
Keyword(s):  
High Frequency ◽  
Sympathetic Activity ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Normal Subjects ◽  
Power Spectral ◽  
Low Frequency Variability ◽  
High Frequency Variability

The exact mechanisms for the decrease in R-R interval (RRI) during acute physiological hyperinsulinemia with euglycemia are unknown. Power spectral analysis of RRI and microneurographic recordings of muscle sympathetic nerve activity (MSNA) in 16 normal subjects provided markers of autonomic control during 90-min hyperinsulinemic/euglycemic clamps. By infusing propranolol and insulin ( n = 6 subjects), we also explored the contribution of heightened cardiac sympathetic activity to the insulin-induced decrease in RRI. Slight decreases in RRI ( P < 0.001) induced by sevenfold increases in plasma insulin could not be suppressed by propranolol. Insulin increased MSNA by more than twofold ( P < 0.001), decreased the high-frequency variability of RRI ( P< 0.01), but did not affect the absolute low-frequency variability of RRI. These results suggest that reductions in cardiac vagal tone and modulation contribute at least in part to the reduction in RRI during hyperinsulinemia. Moreover, more than twofold increases in MSNA occurring concurrently with a slight and not purely sympathetically mediated tachycardia suggest regionally nonuniform increases in sympathetic activity during hyperinsulinemia in humans.

Effect of provocative maneuvers on heart rate variability in subjects with quadriplegia

1995 ◽  
Vol 268 (6) ◽  
pp. H2239-H2245 ◽  
Author(s):  
D. R. Grimm ◽  
R. E. DeMeersman ◽  
R. P. Garofano ◽  
A. M. Spungen ◽  
W. A. Bauman
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sympathetic Activity ◽  
Spectral Component ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Parasympathetic Activity ◽  
Power Spectral ◽  
Spectral Components ◽  
Male Subjects

This study investigated heart rate variability (HRV) in individuals with quadriplegia who have disruption of autonomic control of the heart. Seven male subjects with neurological complete quadriplegia and seven with incomplete quadriplegia were studied at rest and during provocation. HRV was measured by power spectral analysis using a fast Fourier transform. Two spectral components were generated: 1) the high-frequency (HF) peak, a reflection of parasympathetic activity, and 2) the low-frequency (LF) peak, primarily sympathetic activity with some parasympathetic input. Results of the provocative maneuvers were grouped into one composite variable. Significant differences in the LF spectral component were found between the groups with complete and incomplete lesions in the supine position and after provocation (LF supine: P = 0.01; LF provocation: P = 0.002). After provocation, significant differences were demonstrated in the HF spectral component between these groups (P = 0.005). In contrast to previous findings, a LF component in subjects with complete quadriplegia was observed; this LF component decreased after provocation, suggesting the parasympathetic component withdrew during stressful maneuvers. There also appeared to be general downregulation of parasympathetic activity to the heart in subjects with complete quadriplegia. The presence of an increased LF spectral component during provocation in those with incomplete lesions implies sympathetic stimulation of the heart and may be used as a marker of sympathetic activity in individuals with quadriplegia.

Role of sinoaortic afferents in modulating BP and pulse-interval spectral characteristics in unanesthetized cats

1991 ◽  
Vol 261 (6) ◽  
pp. H1811-H1818 ◽  
Author(s):  
M. Di Rienzo ◽  
G. Parati ◽  
P. Castiglioni ◽  
S. Omboni ◽  
A. U. Ferrari ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
High Frequency ◽  
Spectral Characteristics ◽  
Low Frequency ◽  
Pulse Interval ◽  
Very Low Frequency ◽  
Variability Pattern ◽  
Spectral Components ◽  
Related Increase

Sinoaortic denervation (SAD) is accompanied by an increase in blood pressure (BP) and a reduction in pulse-interval (PI) variance. Little is known, however, about the effect of SAD on the complex BP and PI variability pattern, which is identified by spectral analysis. In nine unanesthetized cats in which intra-arterial BP was monitored before and 7-10 days after SAD, spectral powers (estimated by fast Fourier transform) were calculated for the low frequency (LF, 0.025-0.07 Hz), midfrequency (MF, 0.07-0.14 Hz), and high frequency (HF, 0.14-0.60 Hz) band. The very low frequency (VLF) BP and PI components (VLF less than 0.025 Hz) were also estimated. SAD increased systolic BP variance and decreased PI variance. The reduction of PI variance was paralleled by significant and marked reductions in all PI powers including the VLF components. In contrast, the increase in systolic BP variance was accompanied by a marked increase in LF power, a decrease in MF power, and no change in HF power. The VLF BP components increased after SAD for frequencies between 0.025 and 0.0012 Hz, whereas a sudden marked reduction was observed below 0.0012 Hz. Similar results were obtained for diastolic BP powers. Thus the reduction in PI variance induced by SAD is paralleled by a reduction in all PI fluctuations identified by spectral analysis. This is not the case for the SAD-related increase in BP variance, which is accompanied by an increase, no change, or even a reduction in the different BP spectral components.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Power Spectral Analysis of Heart Rate Variability in Adolescent Male Athletes

1970 ◽  
Vol 4 (2) ◽  
pp. 26-33 ◽  
Author(s):  
Md Mashudul Alom ◽  
Noorzahan Begum ◽  
Sultana Ferdousi ◽  
Shelina Begum ◽  
Taskina Ali
Keyword(s):  
Heart Rate ◽  
Spectral Analysis ◽  
Physical Exercise ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Adolescent Male ◽  
Total Power ◽  
Male Athletes ◽  
Power Spectral ◽  
Regular Physical Exercise

Background: Cardiac autonomic nervous activities (CANA) deteriorate with age, obesity, sedentary life style and in various cardiac and noncardiac disease conditions. Regular physical exercise may improve CANA in health and diseases. Power spectral analysis (PSA) of Heart rate variability (HRV) is one of the most promising newer techniques to quantify CANA. Objective: To analyze HRV by Power Spectral method in order to find out the influence of regular physical exercise on CANA in male adolescent athletes. Method: This cross sectional study was carried out on 62 adolescent male athletes aged 12-18 years (group B), in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University from 1st July 2007 to 30th June 2008. For comparison, 30 age, sex, BMI and socioeconomic condition matched apparently healthy sedentary subjects (group A) were also studied. The study subjects were selected from the BKSP (Bangladesh Krira Shikka Prothistan, Savar, Dhaka) and the control from a residential school of Dhaka city.Power spectral measures of HRV including Total Power (TP), Very Low Frequency Power (VLF) Low Frequency (LF), High Frequency (HF) LF/HF were measured by a Polygraph. For statistical analysis, Independent-Sample t-test was used. Results: Total power, HFnu power and the VLF, LF, HF were significantly (P<0.001) higher and LFnu power and the LF/HF ratio were significantly (P<0.001) lower in athletes than those of nonathletes which indicate higher cardiac parasympathetic and lower sympathetic activity in athletes. Conclusion: Cardiac Autonomic regulation with increased parasympathetic and decreased sympathetic modulation may occur with in athletes engaged with regular physical exercise. Key words: Power Spectral Analysis (PSA), CANA, Athlete, Adolescent DOI: 10.3329/jbsp.v4i2.4169 J Bangladesh Soc Physiol. 2009 Dec;4(2): 26-33  

scholarly journals Effects of Remifentanil on Cardiovascular Stimulation Caused by Local Anesthetic With Epinephrine: A Power Spectral Analysis

2020 ◽  
Vol 68 (1) ◽  
pp. 10-18
Author(s):  
Asako Eriguchi ◽  
Nobuyuki Matsuura ◽  
Yoshihiko Koukita ◽  
Tatsuya Ichinohe
Keyword(s):  
Heart Rate ◽  
Spectral Analysis ◽  
Local Anesthesia ◽  
Infusion Rate ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Sagittal Split Ramus Osteotomy ◽  
Remifentanil Infusion ◽  
Power Spectral ◽  
Surgical Field

The objectives of this research were to investigate (a) what was the most effective infusion rate of remifentanil and (b) the degree to which sympathomimetic effects were involved with cardiovascular stimulation by using a power spectral analysis of heart rate variability (HRV). A total of 63 healthy individuals scheduled for sagittal split ramus osteotomy were enrolled and randomly allocated to 1 of 3 groups: remifentanil infusion rate of 0.1, 0.2, or 0.4 μg/kg/min. Anesthesia was maintained with remifentanil and propofol. Before the surgical procedure, 2% lidocaine containing 12.5 μg/mL epinephrine was administered in the surgical field for local anesthesia. Systolic blood pressure (SBP), heart rate (HR), low-frequency (LF) and high-frequency (HF) components in HRV power spectral analysis, and the LF/HF ratio were analyzed. Increases in SBP and HR were observed after local anesthesia in all 3 groups, but no significant differences were observed between the groups. Remifentanil infusion at 0.1 μg/kg/min may be appropriate to minimize cardiovascular stimulation caused by exogenous epinephrine from local anesthesia. Although a rise in the LF/HF ratio was observed after local anesthesia in all groups, no relationship was observed between the cardiovascular changes and the increase in LF/HF ratio. This suggests that sympathomimetic effects are involved to a lesser extent with the cardiovascular stimulation caused by exogenous epinephrine.

Influence of aging on cardiac baroreflex sensitivity determined non-invasively by power spectral analysis

2001 ◽  
Vol 100 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Mauro CACCIAFESTA ◽  
Emanuela VIOLA ◽  
Elvira SANTAGADA ◽  
Marialuce NOCCO ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Baroreflex Sensitivity ◽  
Large Population ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
The Elderly ◽  
Elderly Subjects ◽  
Spectral Window ◽  
Power Spectral ◽  
Effects Of Aging

Aging reduces cardiac baroreflex sensitivity. Our primary aim in the present study was to assess the effects of aging on cardiac baroreflex sensitivity, as determined by power spectral analysis (α index), in a large population of healthy subjects. We also compared the α indexes determined by power spectral analysis with cardiac baroreflex sensitivity measured by the phenylephrine method (BSphen). We studied 142 subjects (79 males/63 females; age range 9–94 years), who were subdivided into five groups according to percentiles of age (25, 50, 75 and 95). Power spectral analysis yields three α indexes: an α low-frequency (LF) index of cardiac baroreflex sensitivity that ranges around 0.1 Hz; an α high-frequency (HF) index reflecting cardiac baroreflex sensitivity corresponding to the respiratory rate; and α total frequency (α TF), a new index whose spectral window includes all power in the range 0.03–0.42 Hz. Spectra were recorded during controlled and uncontrolled respiration. Under both conditions, all three α indexes were higher in the youngest age group (⩽ 34 years old) than in the three oldest groups. Notably, α TF was significantly higher in younger subjects than in the three oldest groups [14±1 ms/mmHg compared with 9±1 (P < 0.05), 8.1±1 (P < 0.001) and 8.1±1 (P < 0.05) ms/mmHg respectively]. BSphen showed a similar pattern [12±1 ms/mmHg compared with 8±0.5 (P < 0.001), 6±0.5 (P < 0.05) and 6±1 (P < 0.05) ms/mmHg respectively]. No significant differences were found for cardiac baroreflex sensitivity among the three oldest groups. All α indexes were correlated inversely with age. The index yielding the closest correlation with BSphen was α TF (r = 0.81, P < 0.001). Cardiac baroreflex sensitivity in normotensive individuals declines with age. It falls predominantly in middle age (from approx. 48 years onwards) and remains substantially unchanged thereafter. The elderly subjects we selected for this study probably had greater resistance to cardiovascular disease that is manifested clinically, with preserved cardiac baroreceptor sensitivity.

Sign in / Sign up

Export Citation Format

Share Document