scholarly journals Gravity Threshold and Dose Response Relationships: Health Benefits Using a Short Arm Human Centrifuge

2021 ◽  
Vol 12 ◽  
Author(s):  
Chrysoula Kourtidou-Papadeli ◽  
Christos A. Frantzidis ◽  
Sotiria Gilou ◽  
Christina E. Plomariti ◽  
Christiane M. Nday ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cardiac Output ◽  
Dose Response ◽  
Neuromuscular Disorders ◽  
Male And Female ◽  
Cardiovascular Parameters ◽  
Cardiac Power ◽  
Cardiovascular Evaluation

PurposeIncreasing the level of gravity passively on a centrifuge, should be equal to or even more beneficial not only to astronauts living in a microgravity environment but also to patients confined to bed. Gravity therapy (GT) may have beneficial effects on numerous conditions, such as immobility due to neuromuscular disorders, balance disorders, stroke, sports injuries. However, the appropriate configuration for administering the Gz load remains to be determined.MethodsTo address these issues, we studied graded G-loads from 0.5 to 2.0g in 24 young healthy, male and female participants, trained on a short arm human centrifuge (SAHC) combined with mild activity exercise within 40–59% MHR, provided by an onboard bicycle ergometer. Hemodynamic parameters, as cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were analyzed, as well as blood gas analysis. A one-way repeated measures ANOVA and pairwise comparisons were conducted with a level of significance p < 0.05.ResultsSignificant changes in heart rate variability (HRV) and its spectral components (Class, Fmax, and VHF) were found in all g loads when compared to standing (p < 0.001), except in 1.7 and 2.0g. There were significant changes in CO, cardiac index (CI), and cardiac power (CP) (p < 0.001), and in MAP (p = 0.003) at different artificial gravity (AG) levels. Dose-response curves were determined based on statistically significant changes in cardiovascular parameters, as well as in identifying the optimal G level for training, as well as the optimal G level for training. There were statistically significant gender differences in Cardiac Output/CO (p = 0.002) and Cardiac Power/CP (p = 0.016) during the AG training as compared to standing. More specifically, these cardiovascular parameters were significantly higher for male than female participants. Also, there was a statistically significant (p = 0.022) gender by experimental condition interaction, since the high-frequency parameter of the heart rate variability was attenuated during AG training as compared to standing but only for the female participants (p = 0.004).ConclusionThe comprehensive cardiovascular evaluation of the response to a range of graded AG loads, as compared to standing, in male and female subjects provides the dose-response framework that enables us to explore and validate the usefulness of the centrifuge as a medical device. It further allows its use in precisely selecting personalized gravity therapy (GT) as needed for treatment or rehabilitation of individuals confined to bed.

scholarly journals The Peculiarities of Heart Rate Variability in Student Athletes

2021 ◽  
Vol 11 (2) ◽  
pp. 169-172
Author(s):  
Andrew Martusevich ◽  
Ivan Bocharin ◽  
Natalia Ronzhina ◽  
Solomon Apoyan ◽  
Levon Dilenyan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Optimal Level ◽  
Track And Field ◽  
Testing System ◽  
Integral Criterion ◽  
Age Range

The aim of this research was to study the peculiarities of heart rate variability (HRV) and microcirculation in students, depending on their sport specialization. Methods and Results: Our study included the results of a survey of 96 students from 18 to 21 years of age who were the members of the national teams of their universities in athletics (n=49) and floorball (n=47). For ECG registration and analysis of hemodynamic findings, including those characterizing the HRV, we used the “Medical Soft” sports testing system (“MS FIT Pro”). For monitoring, we used the standard hemodynamic patterns (blood pressure, HR, stroke volume, cardiac output, and others), statistical and spectral indicators of the HRV, as well as an integral criterion of the state of microcirculation. The studied HRV parameters in most students generally were within the age range. At the same time, track and field athletes have large adaptive resources and, consequently, a more optimal level of myocardial fitness, in comparison with floorball players. Conclusion: The orientation of sports training among students affects heart condition.

Autonomic Cardiovascular Dysregulation at Rest and During Stress in Chronically Low Blood Pressure

2019 ◽  
Vol 33 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Stefan Duschek ◽  
Alexandra Hoffmann ◽  
Casandra I. Montoro ◽  
Gustavo A. Reyes del Paso
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Baroreflex Sensitivity ◽  
Peripheral Resistance ◽  
Control Group ◽  
Low Blood Pressure

Abstract. Chronic low blood pressure (hypotension) is accompanied by symptoms such as fatigue, reduced drive, faintness, dizziness, cold limbs, and concentration difficulties. The study explored the involvement of aberrances in autonomic cardiovascular control in the origin of this condition. In 40 hypotensive and 40 normotensive subjects, impedance cardiography, electrocardiography, and continuous blood pressure recordings were performed at rest and during stress induced by mental calculation. Parameters of cardiac sympathetic control (i.e., stroke volume, cardiac output, pre-ejection period, total peripheral resistance), parasympathetic control (i.e., heart rate variability), and baroreflex function (i.e., baroreflex sensitivity) were obtained. The hypotensive group exhibited markedly lower stroke volume, heart rate, and cardiac output, as well as higher pre-ejection period and baroreflex sensitivity than the control group. Hypotension was furthermore associated with a smaller blood pressure response during stress. No group differences arose in total peripheral resistance and heart rate variability. While reduced beta-adrenergic myocardial drive seems to constitute the principal feature of the autonomic impairment that characterizes chronic hypotension, baroreflex-related mechanisms may also contribute to this state. Insufficient organ perfusion due to reduced cardiac output and deficient cardiovascular adjustment to situational requirements may be involved in the manifestation of bodily and mental symptoms.

The Effects of Caffeine Intake on Cardiovascular Parameters in Sleep Deprived Medical Residents

2019 ◽  
Vol 70 (4) ◽  
pp. 1445-1448
Author(s):  
Ioana Raluca Papacocea ◽  
Ioana Anca Badarau ◽  
Mariana Catalina Ciornei ◽  
Sofia Lider Burciulescu ◽  
Marius Toma Papacocea
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Sleep Deprivation ◽  
Medical Residents ◽  
Caffeine Intake ◽  
Caffeine Consumption ◽  
Cardiovascular Parameters ◽  
Arterial Blood

Physicians and medical residents are particularly affected by sleep deprivation are, especially in East European countries. The aim of our study is to analyze the effect of caffeine intake on cardiovascular functions in sleep deprived residents (clinicians in-training) after continuous 24h on-call duty. 26 medical residents aged between 22-33 years old, 12 men and 14 women, who began their activity at 2 pm were included. Each subject consumed coffee or caffeinated drinks such as Coca cola during this period, after 2 am, expressed in caffeine units. We have evaluated their cardiovascular function using impedance cardiography (ICG-M501) and blood pressure measurement using the manometric method, before (at 7 pm) and after caffeine consumption (at 7 am), during one night of on-call duty. Surprisingly, after caffeine consumption, all subjects have had a decrease of the heart rate after one night of sleep deprivation (from mean: 83 b/min before to 69.73 b/min after, p = 0.000), also the mean arterial blood pressure is lower after the overnight call (from mean: 95.3 mmHg before to 88.9 mmHg after). Moreover, cardiac output, stroke volume and cardiac index decreases along with an increase of peripheral vascular resistance. Caffeine intake exerts a paradoxical effect on sleep deprived subjects; acute sleep loss, due to continuously, intense on-call work, modifies several cardiovascular parameters, such as heart rate, blood pressures, stroke volume and cardiac output.

scholarly journals Differential effects of the blood pressure state on pulse rate variability and heart rate variability in critically ill patients

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Elisa Mejía-Mejía ◽  
James M. May ◽  
Mohamed Elgendi ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Pulse Rate ◽  
Pulse Transit Time ◽  
Pulse Rate Variability ◽  
Physiological Factors ◽  
Ecg Signals ◽  
Non Invasive ◽  
Electrocardiogram Ecg

AbstractHeart rate variability (HRV) utilizes the electrocardiogram (ECG) and has been widely studied as a non-invasive indicator of cardiac autonomic activity. Pulse rate variability (PRV) utilizes photoplethysmography (PPG) and recently has been used as a surrogate for HRV. Several studies have found that PRV is not entirely valid as an estimation of HRV and that several physiological factors, including the pulse transit time (PTT) and blood pressure (BP) changes, may affect PRV differently than HRV. This study aimed to assess the relationship between PRV and HRV under different BP states: hypotension, normotension, and hypertension. Using the MIMIC III database, 5 min segments of PPG and ECG signals were used to extract PRV and HRV, respectively. Several time-domain, frequency-domain, and nonlinear indices were obtained from these signals. Bland–Altman analysis, correlation analysis, and Friedman rank sum tests were used to compare HRV and PRV in each state, and PRV and HRV indices were compared among BP states using Kruskal–Wallis tests. The findings indicated that there were differences between PRV and HRV, especially in short-term and nonlinear indices, and although PRV and HRV were altered in a similar manner when there was a change in BP, PRV seemed to be more sensitive to these changes.

scholarly journals Ethnic and sex differences in the longitudinal association between heart rate variability and blood pressure

2021 ◽  
pp. 1-7
Author(s):  
LaBarron K. Hill ◽  
Julian F. Thayer ◽  
DeWayne P. Williams ◽  
James D. Halbert ◽  
Guang Hao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sex Differences ◽  
Longitudinal Association

A Comparison of the Acute Haemodynamic Effects of Propranolol and Pindolol at Rest and during Supine Exercise in Man

1980 ◽  
Vol 59 (s6) ◽  
pp. 465s-468s ◽  
Author(s):  
T. L. Svendsen ◽  
J. E. Carlsen ◽  
O. Hartling ◽  
A. McNair ◽  
J. Trap-Jensen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Response Curves ◽  
Receptor Blocking ◽  
Artery Pressure ◽  
Arterial Blood ◽  
Β Receptor

1. Dose-response curves for heart rate, cardiac output, arterial blood pressure and pulmonary artery pressure were obtained in 16 male patients after intravenous administration of three increasing doses of pindolol, propranolol or placebo. All patients had an uncomplicated acute myocardial infarction 6–8 months earlier. 2. The dose-response curves were obtained at rest and during repeated bouts of supine bicycle exercise. The cumulative dose amounted to 0.024 mg/kg body weight for pindolol and to 0.192 mg/kg body weight for propranolol. 3. At rest propranolol significantly reduced heart rate and cardiac output by 12% and 15% respectively. Arterial mean blood pressure was reduced by 9.2 mmHg. Mean pulmonary artery pressure increased significantly by 2 mmHg. Statistically significant changes in these variables were not seen after pindolol or placebo. 4. During exercise pindolol and propranolol both reduced cardiac output, heart rate and arterial blood pressure to the same extent. After propranolol mean pulmonary artery pressure was increased significantly by 3.6 mmHg. Pindolol and placebo did not change pulmonary artery pressure significantly. 5. The study suggests that pindolol may offer haemodynamic advantages over β-receptor-blocking agents without intrinsic sympathomimetic activity during low activity of the sympathetic nervous system, and may be preferable in situations where the β-receptor-blocking effect is required only during physical or psychic stress.

scholarly journals Heart rate variability and blood pressure among Japanese men and women: a community-based cross-sectional study

2014 ◽  
Vol 37 (8) ◽  
pp. 779-784 ◽  
Author(s):  
Hiromi Mori ◽  
Isao Saito ◽  
Eri Eguchi ◽  
Koutatsu Maruyama ◽  
Tadahiro Kato ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Community Based ◽  
Cross Sectional ◽  
Japanese Men ◽  
Men And Women

Reproducibility of heart rate variability, blood pressure variability and baroreceptor sensitivity during rest and head-up tilt

2005 ◽  
Vol 10 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Michael V. H??jgaard ◽  
Niels-Henrik Holstein-Rathlou ◽  
Erik Agner ◽  
J??rgen K. Kanters
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Blood Pressure Variability ◽  
Baroreceptor Sensitivity ◽  
Head Up Tilt
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