scholarly journals Day and Night Changes of Cardiovascular Complexity: A Multi-Fractal Multi-Scale Analysis

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 462
Author(s):  
Paolo Castiglioni ◽  
Stefano Omboni ◽  
Gianfranco Parati ◽  
Andrea Faini
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Rehabilitation Medicine ◽  
Fluctuation Analysis ◽  
Multiscale Approach ◽  
Similarity Coefficients ◽  
Short Term ◽  
Night Time ◽  
Nonlinear Components

Recently, a multifractal-multiscale approach to detrended fluctuation analysis (DFA) was proposed to evaluate the cardiovascular fractal dynamics providing a surface of self-similarity coefficients α(q,τ), function of the scale τ, and moment order q. We hypothesize that this versatile DFA approach may reflect the cardiocirculatory adaptations in complexity and nonlinearity occurring during the day/night cycle. Our aim is, therefore, to quantify how α(q, τ) surfaces of cardiovascular series differ between daytime and night-time. We estimated α(q,τ) with −5 ≤ q ≤ 5 and 8 ≤ τ ≤ 2048 s for heart rate and blood pressure beat-to-beat series over periods of few hours during daytime wake and night-time sleep in 14 healthy participants. From the α(q,τ) surfaces, we estimated short-term (<16 s) and long-term (from 16 to 512 s) multifractal coefficients. Generating phase-shuffled surrogate series, we evaluated short-term and long-term indices of nonlinearity for each q. We found a long-term night/day modulation of α(q,τ) between 128 and 256 s affecting heart rate and blood pressure similarly, and multifractal short-term modulations at q < 0 for the heart rate and at q > 0 for the blood pressure. Consistent nonlinearity appeared at the shorter scales at night excluding q = 2. Long-term circadian modulations of the heart rate DFA were previously associated with the cardiac vulnerability period and our results may improve the risk stratification indicating the more relevant α(q,τ) area reflecting this rhythm. Furthermore, nonlinear components in the nocturnal α(q,τ) at q ≠ 2 suggest that DFA may effectively integrate the linear spectral information with complexity-domain information, possibly improving the monitoring of cardiac interventions and protocols of rehabilitation medicine.

Fetal responses to long-term hypoxemia in sheep

1989 ◽  
Vol 256 (6) ◽  
pp. R1348-R1354 ◽  
Author(s):  
T. Kitanaka ◽  
J. G. Alonso ◽  
R. D. Gilbert ◽  
B. L. Siu ◽  
G. K. Clemons ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Brachiocephalic Artery ◽  
Short Term ◽  
Control Value ◽  
Cardiovascular Hemodynamics ◽  
Arterial Blood ◽  
Body Weights ◽  
Arterial Po2

The effect of acute or short-term hypoxia on fetal cardiovascular hemodynamics has been well known; however, little is known about the effect of long-term hypoxemia. To determine the fetal hemodynamic responses to this stress we studied two groups of animals: 1) pregnant ewes (n = 20) at 110-115 days of gestation subjected to hypoxia for up to 28 days and 2) pregnant ewes (n = 4) that served as normoxic controls. We chronically catheterized the fetal brachiocephalic artery and vein. Five to 6 days after surgery, control measurements were made of mean arterial blood pressure, heart rate, arterial PO2, O2 saturation, hemoglobin, hematocrit, blood volume, and the concentrations of erythropoietin, cortisol, epinephrine, and norepinephrine. The next day the ewes were placed in a chamber with an inspired O2 fraction of 12-13%. Within a few minutes fetal arterial PO2 decreased from control value of 29.7 +/- 2.1 to 19.1 +/- 2.1 Torr, where it remained. Hemoglobin increased from 10.0 +/- 1.0 to 12.9 +/- 1.9 g/dl by day 7, where it remained. This was associated with an increase of erythropoietin from 22.8 +/- 2.2 to 144 +/- 37 mU/ml within 24 h, but by day 7 it had returned to levels slightly above normal. Epinephrine also increased moderately and remained elevated throughout the study. However, values of mean arterial pressure and heart rate did not differ from controls. Perhaps surprisingly, these fetuses were able to compensate so that at term their body weights were normal, 3.77 +/- 0.2 kg.

scholarly journals INVESTIGATION OF HEART RATE VARIABILITY BY STATISTICAL METHODS AND DETRENDED FLUCTUATION ANALYSIS

2019 ◽  
Vol 7 ◽  
Author(s):  
Galya Nikolova Georgieva-Tsaneva
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Statistical Methods ◽  
Detrended Fluctuation Analysis ◽  
Age Groups ◽  
Research Problem ◽  
Fluctuation Analysis ◽  
Short Term ◽  
Detrended Fluctuation

The physiological signals that are recorded from different parts of the human body have a non-stationary nature and the tracking of their dynamics is an interesting research problem. This report examines Heart Rate Variability through the use of statistical methods of analysis that are traditionally used to study the functionality of the heart and via Detrended Fluctuation Analysis. The use of the technique of Detrended Fluctuation Analysis allows the investigation of short-term and long-term correlations in non-stationary Heart Rate Variability series. A study has been made of the changes in the functioning of the human heart, depending on the age. The study encompasses healthy individuals in three different age groups. The analysis of the obtained results shows a change in the correlated behavior of the investigated signals with an increase in age.

Long- and Short-Term Blood Pressure and Rr-Interval Variability and Psychosomatic Distress in Chronic Fatigue Syndrome

1998 ◽  
Vol 94 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Daniel A. Duprez ◽  
Marc L. De Buyzere ◽  
Benny Drieghe ◽  
Friedl Vanhaverbeke ◽  
Youri Taes ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Chronic Fatigue Syndrome ◽  
Chronic Fatigue ◽  
Standing Position ◽  
Spectral Indices ◽  
Short Term ◽  
Night Time ◽  
Rr Interval ◽  
Fatigue Syndrome

1. Chronic low blood pressure has been associated with fatigue and low mood. However, in the chronic fatigue syndrome (CFS) the blood pressure (BP) and heart rate profile and their variabilities have not been characterized as yet. 2. We performed office and 24 h ambulatory BP recordings in 38 subjects (age, 34.8 ± 8.0 years) who fulfilled the Holmes criteria for CFS and in 38 healthy control subjects (age 35.6 ± 10.5 years), as well as short-term beat-to-beat BP and RR-interval recordings for 10 min in supine and standing position, and calculated spectral indices. 3. In CFS office (123 ± 19/70 ± 12 mmHg) as well as 24-h, day- and night-time blood pressure values (116 ± 11.1/71 ± 11.1, 121 ± 9.2/77 ± 8.0 and 110 ± 10.5/65 ± 9.2 mmHg respectively) were within reference limits. 4. Heart rate was consistently higher (P < 0.01) in CFS patients, based on both office (77 ± 12 compared with 68 ± 12 beats min−-1) and 24 h ambulatory recordings (77 ± 12 compared with 67 ± 15 beats min−-1). 5. In supine position, spectral indices of BP variability (total, low-frequency and high-frequency variances) were all significantly (P < 0.01) lower in CFS. In standing position the differences disappeared. Analysis of RR-interval variability could not detect major alterations in autonomic function in CFS.

scholarly journals Paleolithic Diet—Effect on the Health Status and Performance of Athletes?

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1019
Author(s):  
Barbara Frączek ◽  
Aleksandra Pięta ◽  
Adrian Burda ◽  
Paulina Mazur-Kurach ◽  
Florentyna Tyrała
Keyword(s):  
Blood Pressure ◽  
Body Mass ◽  
Positive Impact ◽  
Model Assessment ◽  
Paleolithic Diet ◽  
Short Term ◽  
Positive Effects ◽  
Short And Long Term ◽  
The Impact

The aim of this meta-analysis was to review the impact of a Paleolithic diet (PD) on selected health indicators (body composition, lipid profile, blood pressure, and carbohydrate metabolism) in the short and long term of nutrition intervention in healthy and unhealthy adults. A systematic review of randomized controlled trials of 21 full-text original human studies was conducted. Both the PD and a variety of healthy diets (control diets (CDs)) caused reduction in anthropometric parameters, both in the short and long term. For many indicators, such as weight (body mass (BM)), body mass index (BMI), and waist circumference (WC), impact was stronger and especially found in the short term. All diets caused a decrease in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG), albeit the impact of PD was stronger. Among long-term studies, only PD cased a decline in TC and LDL-C. Impact on blood pressure was observed mainly in the short term. PD caused a decrease in fasting plasma (fP) glucose, fP insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) and glycated hemoglobin (HbA1c) in the short run, contrary to CD. In the long term, only PD caused a decrease in fP glucose and fP insulin. Lower positive impact of PD on performance was observed in the group without exercise. Positive effects of the PD on health and the lack of experiments among professional athletes require longer-term interventions to determine the effect of the Paleo diet on athletic performance.

Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis

2021 ◽  
pp. 089686082199692
Author(s):  
Vasilios Vaios ◽  
Panagiotis I Georgianos ◽  
Georgia Vareta ◽  
Dimitrios Divanis ◽  
Evangelia Dounousi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Heart Rate ◽  
Peritoneal Dialysis ◽  
Kidney Disease ◽  
Pulse Wave ◽  
Age Dependence ◽  
End Stage Kidney Disease ◽  
End Stage

Background: The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood. Methods: In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis. Results: In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age ( β: 0.883), 24-h systolic blood pressure (BP) ( β: 0.217) and 24-h heart rate ( β: −0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R 2 = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons. Conclusion: The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.

Diurnal Blood Pressure Variation in Quadriplegic Chronic Spinal Cord Injury Patients

1991 ◽  
Vol 80 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Henry Krum ◽  
William J. Louis ◽  
Douglas J. Brown ◽  
Graham P. Jackman ◽  
Laurence G. Howes
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Spinal Cord Injury ◽  
Ambulatory Monitoring ◽  
Pressure Variation ◽  
Night Time ◽  
Cord Injury ◽  
Blood Pressure Variation ◽  
Neurologically Intact

1. Measurement of blood pressure and heart rate over a 24 h period was peformed in 10 quadriplegic spinal cord injury patients and 10 immobilized, neurologically intact orthopaedic subjects by using the Spacelabs 90207 automated ambulatory monitoring system. 2. Systolic and diastolic blood pressure fell significantly at night in orthopaedic subjects but not in quadriplegic patients, and night-time blood pressures were similar in both groups. 3. Cumulative summation of differences from a reference value (cusum analysis) confirmed a markedly diminished diurnal blood pressure variation in the quadriplegic patients. 4. These findings could not be accounted for on the basis of blood pressure variations during chronic postural change. 5. Heart rate fell significantly at night in both groups. 6. The findings suggest that the increase in blood pressure during waking hours in neurologically intact subjects is a consequence of a diurnal variation in sympathetic activity (absent in quadriplegic patients with sympathetic decentralization) which is independent of changes in physical activity.

ABPM Comparison of the Anti-Hypertensive Profiles of Telmisartan and Enalapril in Patients with Mild-to-Moderate Essential Hypertension

2002 ◽  
Vol 30 (6) ◽  
pp. 543-552 ◽  
Author(s):  
J Amerena ◽  
S Pappas ◽  
J-P Ouellet ◽  
L Williams ◽  
D O'Shaughnessy
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Blood Pressure Monitoring ◽  
Study Drug ◽  
Pressure Control ◽  
Moderate Essential Hypertension ◽  
Open Label ◽  
Night Time ◽  
Once Daily

In this multicentre, prospective, randomized, open-label, blinded-endpoint (PROBE) study, the efficacy of 12 weeks' treatment with once-daily telmisartan 40–80 mg and enalapril 10–20 mg was evaluated using ambulatory blood pressure monitoring (ABPM) in 522 patients with mild-to-moderate essential hypertension. Patients were titrated to the higher dose of study drug at week 6 if mean seated diastolic blood pressure (DBP) was ≥ 90 mmHg. The primary endpoint was the change from baseline in ambulatory DBP in the last 6 h of the 24-h dosing interval after 12 weeks' treatment. Telmisartan and enalapril produced similar reductions from baseline in DBP and systolic blood pressure (SBP) over all ABPM periods evaluated (last 6 h, 24-h, daytime and night-time). Telmisartan produced a significantly greater reduction in mean seated trough DBP, measured unblinded with an automated ABPM device in the clinic, amounting to a difference of −2.02 mmHg ( P < 0.01). A significantly greater proportion of patients achieved a seated diastolic response with telmisartan than enalapril (59% versus 50%; P < 0.05), also measured with the same ABPM device. Both treatments were well tolerated. Compared with telmisartan, enalapril was associated with a higher incidence of cough (8.9% versus 0.8%) and hypotension (3.9% versus 1.1%). Therefore, telmisartan may provide better long-term compliance and, consequently, better blood pressure control than enalapril.

Hypoxic pressor response, cardiac size, and natriuretic peptides are modified by long-term intermittent hypoxia

1999 ◽  
Vol 87 (6) ◽  
pp. 2025-2031 ◽  
Author(s):  
Holger Kraiczi ◽  
Jarkko Magga ◽  
Xiang Ying Sun ◽  
Heikki Ruskoaho ◽  
Xiaohe Zhao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Weight ◽  
Atrial Natriuretic Peptide ◽  
Right Ventricular ◽  
Natriuretic Peptide ◽  
Intermittent Hypoxia ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

We investigated whether the effect of long-term intermittent hypoxia (LTIH) on cardiovascular function may be modified by preexisting genetic traits. To induce LTIH experimentally, cycles of 90-s hypoxia (nadir 6%) followed by 90-s normoxia were applied to six Wistar-Kyoto and six spontaneously hypertensive rats during 8 h daily. Comparison with the same number of control animals after 70 days revealed no alteration of intra-arterial blood pressure or heart rate. Blood pressure responsiveness to a brief hypoxic stimulus was enhanced in the LTIH animals, regardless of strain, whereas the hypoxia-induced increase in heart rate was abolished. In the spontaneously hypertensive but not the Wistar-Kyoto rats, LTIH increased left ventricular weight-to-body weight ratio and content of atrial natriuretic peptide mRNA. Expression of B-type natriuretic peptide was unchanged (Northern blot). Slightly increased right ventricular weight-to-body weight ratios in the LTIH animals were associated with higher right ventricular atrial natriuretic peptide and B-type natriuretic peptide mRNA amounts. Consequently, the effects of LTIH on different components of cardiovascular function appear incompletely related to each other and differentially influenced by constitutional traits.

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