Heart rate spectral analysis of fasting-induced bradycardia of cattle

The autonomic mechanisms of fasting-induced bradycardia of cattle were studied using heart rate spectral analysis. This was performed on digitized, lead II, surface electrocardiograms from conscious, fed, and 48-h-fasted adult cows. Fasting resulted in a significant (P less than 0.05) decrease in resting heart rate and a significant (P = 0.0041) increase in low frequency (0-90 mHz) power spectral area. Administration of atropine sulfate (0.02 mg/kg iv) in either the fed or fasted state resulted in a significant (P less than 0.001) decrease in both low-frequency and high-frequency (100-400 mHz) power spectral areas. Significant (P less than 0.05) increases in serum total bilirubin, inorganic phosphorus, and total protein were associated with fasting. Significant decreases were seen in fasting serum aspartate aminotransferase and potassium values. Manual evacuation of the rumen of seven steers with chronic rumen fistulae resulted in a mean percent decrease in heart rate of 22 +/- 0.9% (mean +/- SE). These results indicate that in normal cattle a decrease in ruminorecticular fill results in a reflex slowing of the heart rate, due predominantly to an increase in parasympathetic tone.

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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

Clinical Science ◽

10.1042/cs0910035 ◽

1996 ◽

Vol 91 (1) ◽

pp. 35-43 ◽

Cited By ~ 56

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.

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

Bangladesh Medical Journal ◽

10.3329/bmj.v43i3.26298 ◽

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

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Power Spectral Analysis of Heart Rate Variability in Adolescent Male Athletes

Journal of Bangladesh Society of Physiologist ◽

10.3329/jbsp.v4i2.4169 ◽

1970 ◽

Vol 4 (2) ◽

pp. 26-33 ◽

Cited By ~ 2

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

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

Anesthesia Progress ◽

10.2344/anpr-67-03-10 ◽

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.

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