scholarly journals Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Author(s):  
Laura M. J. Fernandez ◽  
Sandro Lecci ◽  
Romain Cardis ◽  
Gil Vantomme ◽  
Elidie Béard ◽  
...  
2017 ◽  
Vol 95 (4) ◽  
pp. 349-355 ◽  
Author(s):  
Luke Anthony Rannelli ◽  
Jennifer M. MacRae ◽  
Michelle C. Mann ◽  
Sharanya Ramesh ◽  
Brenda R. Hemmelgarn ◽  
...  

Diabetes confers greater cardiovascular risk to women than to men. Whether insulin-resistance-mediated risk extends to the healthy population is unknown. Measures of insulin resistance (fasting insulin, homeostatic model assessment, hemoglobin A1c, quantitative insulin sensitivity check index, glucose) were determined in 48 (56% female) healthy subjects. Heart rate variability (HRV) was calculated by spectral power analysis and arterial stiffness was determined using noninvasive applanation tonometry. Both were measured at baseline and in response to angiotensin II infusion. In women, there was a non-statistically significant trend towards increasing insulin resistance being associated with an overall unfavourable HRV response and increased arterial stiffness to the stressor, while men demonstrated the opposite response. Significant differences in the associations between insulin resistance and cardiovascular physiological profile exist between healthy women and men. Further studies investigating the sex differences in the pathophysiology of insulin resistance in cardiovascular disease are warranted.


2021 ◽  
Vol 29 (3) ◽  
pp. 369-378
Author(s):  
Aleksej A. Nizov ◽  
Aleksej I. Girivenko ◽  
Mihail M. Lapkin ◽  
Aleksej V. Borozdin ◽  
Yana A. Belenikina ◽  
...  

BACKGROUND: The search for rational methods of primary, secondary, and tertiary prevention of coronary heart disease. To date, there are several publications on heart rate variability in ischemic heart disease. AIM: To study the state of the regulatory systems in the organism of patients with acute coronary syndrome without ST segment elevation based on the heart rhythm, and their relationship with the clinical, biochemical and instrumental parameters of the disease. MATERIALS AND METHODS: The open comparative study included 76 patients (62 men, 14 women) of mean age, 61.0 0.9 years, who were admitted to the Emergency Cardiology Department diagnosed of acute coronary syndrome without ST segment elevation. On admission, cardiointervalometry was performed using Varicard 2.51 apparatus, and a number of clinical and biochemical parameters were evaluated RESULTS: Multiple correlations of parameters of heart rate variability and clinical, biochemical and instrumental parameters were observed. From this, a cluster analysis of cardiointervalometry was performed, thereby stratifying patients into five clusters. Two extreme variants of dysregulation of the heart rhythm correlated with instrumental and laboratory parameters. A marked increase in the activity of the subcortical nerve centers (maximal increase of the spectral power in the very low frequency range with the underlying reduction of SDNN) in cluster 1 was associated with reduction of the left ventricular ejection fraction: cluster 147.0 [40.0; 49.0], cluster 260.0 [58.0; 64.0], cluster 360.0 [52.5; 64.5] % (the data are presented in the form of median and interquartile range; Me [Q25; Q75], p 0,05). Cluster 5 showed significant reduction in SDNN (monotonous rhythm), combined with increased level of creatine phosphokinase (CPC): cluster 5446,0 [186.0; 782.0], cluster 4141.0 [98.0; 204.0] IU/l; Me [Q25; Q75], p 0.05) and MВ-fraction of creatine phosphokinase; cluster 532.0 [15.0; 45.0], 4 cluster 412.0 [9.0; 18.0] IU/l; Me [Q25; Q75], p 0.05). CONCLUSIONS: In patients with acute coronary syndrome without ST segment elevation, cluster analysis of parameters of heart rate variability identified different peculiarities of regulation of the heart rhythm. Pronounced strain of the regulatory systems of the body was found to be associated with signs of severe pathology: the predominance of VLF (spectral power of the curve enveloping a dynamic range of cardiointervals in the very low frequency range) in spectral analysis with an underlying reduced SDNN is characteristic of patients with a reduced ejection fraction, and a monotonous rhythm is characteristic of patients with an increased level of creatine phosphokinase and MB-fraction of creatine phosphokinase.


2006 ◽  
Vol 75 (1) ◽  
pp. 3-12 ◽  
Author(s):  
J. Mokrý ◽  
T. Remeňová ◽  
K. Javorka

The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA) system and autonomic nervous system (ANS) to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla) were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz), low (LF; 0.05-0.15 Hz) and high frequency bands (HF; 0.15-2.0 Hz) was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine) position, in orthostasis (the angle of 60 °) and again in supine position before and after enalapril (0.5 mg/kg b.w.), metipranolol (0.2 mg/kg b.w.), and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.


1996 ◽  
Vol 271 (4) ◽  
pp. H1555-H1564 ◽  
Author(s):  
A. P. Blaber ◽  
R. L. Bondar ◽  
R. Freeman

We examined heart rate and blood pressure variability (HRV and BPV) during graded tilt (5 min in each position: supine, -10 degrees, 10 degrees, 30 degrees, 60 degrees, -10 degrees, supine) in autonomic failure patients and age-matched controls. Heart rate was not different between patients and controls and increased with tilt (P < 0.001). Total HRV was reduced in patients (P < 0.03). Patients had reduced low-frequency (0-0.15 Hz) HRV and BPV (P < 0.005). With tilt, low-frequency BPV increased in controls, whereas high-frequency (> 0.15 Hz) BPV increased in patients. The slope of the fractal component (beta) for HRV and BPV was not different between patients and controls. HRV-beta increased (1.5-1.9, P < 0.01) with tilt, but BPV-beta (approximately 1.8) was unaffected. Values of beta close to 1 indicate high signal regulatory complexity, and values of beta close to 2 indicate low complexity. HRV and BPV provide clear evidence of impaired sympathetic and parasympathetic autonomic nervous system response to tilt with autonomic failure. The similarity in signal complexity with reduced fractal and harmonic spectral power, in patients compared with controls, suggests unchanged cardiovascular neural input and integration with reduced output in autonomic failure.


2016 ◽  
Vol 16 (1) ◽  
pp. 22-29 ◽  
Author(s):  
T Vasicko ◽  
J Prindesova-Busikova ◽  
O Osina

Abstract Introduction: Heavy working conditions and many unpropitious factors influencing workers health participate in development of various health disorders, among other autonomic cardiovascular regulation malfunction. The aim of this study is to draw a comparison of autonomic nervous system functional age and heart rate variability changes between workers with and without mining occupational exposure. Material and methods: Short term HRV was measured by DiANS PF8 device in men with and without occupational mining exposure (exposure for 10 years at least) using standard orthoclinostathic protocol (each phase 300 sec or 300 heartbeats if heart rate under 60 bpm), excluding those with severe cardiovascular, metabolic, or psychiatric diseases, nicotine and other drugs abuse, as well as those, who underwent heavy stress situation during last year. Results: Evaluating 41 HRV records among miners (n=24, age 47.9 ± 6.1 years, exposure 22.5 ± 5 years) and non-miners (n=17, age 48.5 ± 6.9 years) we found significantly increased difference between functional age of ANS and calendar age in miners group (+7.2 ± 7.3 years) over against the non-miners group (−1.6 ± 6.5 years). No correlation was found between exposure duration and functional age of ANS difference. Analysis of HRV parameters show significant reduction in total spectral power, LF, HF and rMSSD in mine workers above 48 years of age. Discussion and conclusion: Our results show that influence of occupational work factors from mining exposure can clearly take part in worsening the reactivity of ANS, which can be associated with greater risk of developing mostly cardiovascular diseases. It is important to think of non-occupational factors improving or deteriorating ANS reactivity and of individual sensitivity to other external factors.


2017 ◽  
Vol 27 (9) ◽  
pp. 1662-1669 ◽  
Author(s):  
Cagdas Vural ◽  
Ener Cagri Dinleyici ◽  
Pelin Kosger ◽  
Ozge Bolluk ◽  
Zubeyir Kilic ◽  
...  

AbstractIntroductionCarbon monoxide poisoning may cause myocardial toxicity and cardiac autonomic dysfunction, which may contribute to the development of life-threatening arrhythmias. We investigated the potential association between acute carbon monoxide exposure and cardiac autonomic function measured by heart rate variability.MethodThe present study included 40 children aged 1–17 years who were admitted to the Pediatric Intensive Care Unit with acute carbon monoxide poisoning and 40 healthy age- and sex-matched controls. Carboxyhaemoglobin and cardiac enzymes were measured at admission. Electrocardiography was performed on admission and discharge, and 24-hour Holter electrocardiography was digitally recorded. Heart rate variability was analysed at both time points – 24-hour recordings – and frequency domains – from the first 5 minutes of intensive care unit admission.ResultsTime domain and frequency indices such as high-frequency spectral power and low-frequency spectral power were similar between patient and control groups (p>0.05). The ratio of low-frequency spectral power to high-frequency spectral power was significantly lower in the carbon monoxide poisoning group (p<0.001) and was negatively correlated with carboxyhaemoglobin levels (r=−0.351, p<0.05). The mean heart rate, QT dispersion, corrected QT dispersion, and P dispersion values were higher in the carbon monoxide poisoning group (p<0.05) on admission. The QT dispersion and corrected QT dispersion remained longer in the carbon monoxide poisoning group compared with controls on discharge (p<0.05).ConclusionThe frequency domain indices, especially the ratio of low-frequency spectral power to high-frequency spectral power, are useful for the evaluation of the cardiac autonomic function. The decreased low-frequency spectral power-to-high-frequency spectral power ratio reflects a balance of the autonomic nervous system, which shifted to parasympathetic components.


2001 ◽  
Vol 101 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Gianfranco PICCIRILLO ◽  
Mauro CACCIAFESTA ◽  
Marco LIONETTI ◽  
Marialuce NOCCO ◽  
Vincenza DI GIUSEPPE ◽  
...  

As QT variability increases and heart rate variability diminishes, the QT variability index (QTVI)-a non-invasive measure of beat-to-beat fluctuations in QT interval on a single ECG lead-shows a trend towards positive values. Increased QT variability is a risk factor for sudden death. Aging lengthens the QT interval and reduces RR-interval variability. In the present study we investigated the influence of aging and the autonomic nervous system on QT-interval variability in healthy subjects. We studied 143healthy subjects, and divided them into two age ranges (younger and older than 65 years). For each subject we measured two QTVIs: from the q wave to the end of the T wave (QTeVI) and to the apex of the T wave (QTaVI). Both indexes were calculated at baseline and after sympathetic stress. In 10 non-elderly subjects, both QTVIs were determined after β-adrenoreceptor blockade induced by intravenous infusion of propranolol or sotalol. The QTVI was higher in elderly than in younger subjects (P < 0.001). QTVIs obtained during sympathetic stress remained unchanged in the elderly, but became more negative in the younger group (P < 0.05). QTeVI and QTaVI at baseline were correlated positively with age (P < 0.01) and anxiety scores (P < 0.05), but inversely with the low-frequency spectral power of RR-interval variability (P < 0.001). QTVIs were higher in subjects with higher anxiety scores. In younger subjects, sotalol infusion increased both QTVIs significantly, whereas propranolol infusion did not. In conclusion, aging increases QT-interval variability. Whether this change is associated with an increased risk of sudden death remains unclear. The association of abnormal QT-interval variability with anxiety and with reduced low-frequency spectral power of heart rate variability merits specific investigation. In healthy non-elderly subjects, acute sympathetic stress (tilt) decreases the QTVI. β-Adrenoreceptor blockade inhibits this negative trend, thus showing its sympathetic origin. Because a negative trend in QTVI induced by sympathetic stress increases only in younger subjects, it could represent a protective mechanism that is lost with aging.


1997 ◽  
Vol 92 (6) ◽  
pp. 543-550 ◽  
Author(s):  
Gary C. Butler ◽  
Shin-Ichi Ando ◽  
John S. Floras

1. There is a substantial non-harmonic or fractal component to the variability of both heart rate and blood pressure in normal subjects. Heart rate is the more complex of these two signals, with respect to the slope, β, of the 1/fβ relationship. In congestive heart failure, heart rate spectral power is attenuated, but the fractal and harmonic components of heart rate and systolic blood pressure variability have not been characterized. 2. Two groups, each comprising 20 men, were studied during 15 min of supine rest and spontaneous respiration: one with functional class II—IV heart failure (age 52 ± 2 years; mean ± SEM) and a second group of healthy men (age 46 ± 2 years). 3. Total spectral power for heart rate was significantly reduced in heart failure (P < 0.02), whereas total spectral power for systolic blood pressure was similar in the two groups. In both heart failure and normal subjects, 65–80% of total spectral power in these two signals displayed fractal characteristics. 4. In heart failure, the slope of the 1/fβ relationship for heart rate was significantly steeper than in normal subjects (1.40 ± 0.08 compared with 1.14 ± 0.05; P < 0.05), indicating reduced complexity of the fractal component of heart rate variability. There was no significant difference in the 1/fβ slope for systolic blood pressure variability between these two groups, but the blood pressure signals were less complex than heart rate variations in both heart failure (2.31 ± 0.15; P < 0.006) and normal subjects (2.47 ± 0.15; P < 0.0001). 5. Parasympathetic nervous system activity, as estimated from heart rate variability was reduced (P < 0.01) in patients with heart failure, whereas trends towards increased sympathetic nervous system activity and decreased non-harmonic power were not significant. 6. The non-harmonic components of cardiac frequency are reduced in heart failure. Non-harmonic power is not attenuated, but the complexity of the heart rate signal is less than in subjects with normal ventricular function. A reduction in parasympathetic modulation appears to contribute to this loss of complexity of heart rate. Consequently, the heart rate signal comes to resemble that of blood pressure. In contrast, the variability and complexity of the systolic blood pressure signal is similar in heart failure and normal subjects. This reduced complexity of heart rate variability may have adverse implications for patients with heart failure.


1999 ◽  
Vol 91 (6) ◽  
pp. 1604-1604 ◽  
Author(s):  
Isabelle Constant ◽  
Marie-Claude Dubois ◽  
Véronique Piat ◽  
Marie-Laure Moutard ◽  
Maggie McCue ◽  
...  

Background This study was design to assess clinical agitation, electroencephalogram (EEG) and autonomic cardiovascular activity changes in children during induction of anesthesia with sevoflurane compared with halothane using noninvasive recording of EEG, heart rate, and finger blood pressure. Methods Children aged 2-12 yr premedicated with midazolam were randomly assigned to one of three induction techniques: 7% sevoflurane in 100% O2 (group SevoRAPID); 2%, 4%, 6%, and 7% sevoflurane in 100% O2 (group SevoINCR); or 1%, 2%, 3%, and 3.5% halothane in 50% N2O-50% O2 (group HaloN2O). An additional group of children who received 7% sevoflurane in 50% N2O-50% O2 (group SevoN2O) was enrolled after completion of the study. Induction was videotaped. EEG, heart rate, and finger blood pressure were continuously recorded during induction until 5 min after tracheal intubation and analyzed in frequency domain using spectral analysis. Results Agitation was more frequent when anesthesia was induced with 100% O2 compared to the mixture of oxygen and nitrous oxide. No seizures were recorded in any group. In the four groups, induction of anesthesia was associated with an increase in EEG total spectral power and a shift toward the low-frequency bands. Sharp slow waves were present on EEG tracings of the three sevoflurane groups, whereas slow waves and fast rhythms (spindles) were observed in the halothane group. Sevoflurane induced a greater withdrawal of parasympathetic activity than halothane and a transient relative increase in sympathetic vascular tone at loss of eyelash reflex. Conclusions Agitation observed during sevoflurane induction was not associated with seizures. Sevoflurane induction induced a marked inhibition of parasympathetic control of heart rate.


2017 ◽  
Vol 18 (3.1) ◽  
pp. 203-209
Author(s):  
A.I. Lukina

It is established hat changing of parameters of student’s electrocardiogram during the exam are shown by shortening of the intervals RR, QT, PQ, and the complex QRS, thus expressiveness of reactions dominates in sample of lefthanders and ambidexters. The values of wave parameters of heart rate variability, including spectral power of heart rate fluctuations in different frequency ranges, increase in left-handers, while ambidexterity and right handed down. The values of statistical indices of HRV, including SDNN, RMSSD and mode cardio intervals in students during the exam are reduced, and also to a greater extent, and ambidexterity for lefties. These changes corresponded to increasing trend of the index and the activity coefficient Baevsky sympathetic nervous system, indicating a greater intensity of regulatory mechanisms in individuals with left profile of motor domination.


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