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Wildenbeest FWH, Hassing GJ, Kemme MJB, Moerland M, Gal P. Heart rate stability in a clinical setting and after a short exercise in healthy male volunteers. Clin Physiol Funct Imaging 2024; 44:36-43. [PMID: 37458374 DOI: 10.1111/cpf.12846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/21/2023] [Accepted: 07/04/2023] [Indexed: 08/08/2023]
Abstract
INTRODUCTION Limited data exist on heart rate stabilization in the domiciled nature of phase I clinical studies, particularly when frequent measurements of QT intervals are involved. The present analysis aimed to evaluate heart rate stability in the domiciled nature of, and stabilization after a short exercise. METHODS Fifty-six healthy male subjects were included in this analysis. Data during a domiciled clinical setting and after a short exercise were analysed. Mean values of 30 s intervals of collected electrocardiographical data (PR, RR, QT and QTcF intervals) during a 10-min supine resting period in a domiciled nature or after walking up and down three stories (100 steps) were compared to baseline values using paired t-tests or compared to the intrasubject standard deviation. RESULTS Stable heart rates and stable QTcF intervals observed immediately upon assuming a supine position in the domiciled clinical setting. After the short exercise, PR interval and RR interval were significantly (p < 0.05) shorter for up to 120 s (mean value -9.8 ± 7.2 ms) and 30 s (-160 ± 165 ms, p < 0.05), respectively. QT and QTcF intervals were significantly (p < 0.05) shorter for up to 90 and 120 s postexercise, respectively. Both QT and QTcF intervals stabilized after 2 min, but QT interval remained prolonged while QTcF interval returned to baseline levels. CONCLUSION In a clinical setting, male volunteers do not require a waiting period for electrocardiographic parameter normalization. However, accurate measurement of these parameters following a short exercise necessitates a minimum 2-min resting interval.
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Affiliation(s)
| | - Gert-Jan Hassing
- Centre for Human Drug Research, Leiden, The Netherlands
- Leiden University Medical Center, Leiden, The Netherlands
| | - Michiel J B Kemme
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Matthijs Moerland
- Centre for Human Drug Research, Leiden, The Netherlands
- Leiden University Medical Center, Leiden, The Netherlands
| | - Pim Gal
- Centre for Human Drug Research, Leiden, The Netherlands
- Leiden University Medical Center, Leiden, The Netherlands
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Saloň A, Çiftci GM, Zubac D, Šimunič B, Pišot R, Narici M, Fredriksen PM, Nkeh-Chungag BN, Sourij H, Šerý O, Schmid-Zalaudek K, Steuber B, De Boever P, Goswami N. Retinal venular vessel diameters are smaller during ten days of bed rest. Sci Rep 2023; 13:19258. [PMID: 37935771 PMCID: PMC10630473 DOI: 10.1038/s41598-023-46177-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/28/2023] [Indexed: 11/09/2023] Open
Abstract
Older individuals experience cardiovascular dysfunction during extended bedridden hospital or care home stays. Bed rest is also used as a model to simulate accelerated vascular deconditioning occurring during spaceflight. This study investigates changes in retinal microcirculation during a ten-day bed rest protocol. Ten healthy young males (22.9 ± 4.7 years; body mass index: 23.6 ± 2.5 kg·m-2) participated in a strictly controlled repeated-measures bed rest study lasting ten days. High-resolution images were obtained using a hand-held fundus camera at baseline, daily during the 10 days of bed rest, and 1 day after re-ambulation. Retinal vessel analysis was performed using a semi-automated software system to obtain metrics for retinal arteriolar and venular diameters, central retinal artery equivalent and central retinal vein equivalent, respectively. Data analysis employed a mixed linear model. At the end of the bed rest period, a significant decrease in retinal venular diameter was observed, indicated by a significantly lower central retinal vein equivalent (from 226.1 µm, CI 8.90, to 211.4 µm, CI 8.28, p = .026), while no significant changes in central retinal artery equivalent were noted. Prolonged bed rest confinement resulted in a significant (up to 6.5%) reduction in retinal venular diameter. These findings suggest that the changes in retinal venular diameter during bedrest may be attributed to plasma volume losses and reflect overall (cardio)-vascular deconditioning.
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Affiliation(s)
- Adam Saloň
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Göktuğ Mert Çiftci
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Department of Psychiatry, University Hospital Münster, Münster, Germany
| | - Damir Zubac
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
- Department 1 of Internal Medicine, Centre for Integrated Oncology, Aachen, Bonn, Cologne, Düsseldorf, University Hospital of Cologne, Cologne, Germany
| | - Boštjan Šimunič
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
| | - Rado Pišot
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
| | - Marco Narici
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Per Morten Fredriksen
- Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Benedicta Ngwenchi Nkeh-Chungag
- Department of Biological and Environmental Sciences, Faculty of Health Sciences, Walter Sisulu University PBX1, Mthatha, 5117, South Africa
| | - Harald Sourij
- Internal Medicine, Division of Endocrinology and Diabetology, Interdisciplinary Metabolic Medicine Trials Unit, Medical University of Graz, Graz, Austria
| | - Omar Šerý
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Veveří 97, 602 00, Brno, Czech Republic
| | - Karin Schmid-Zalaudek
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Bianca Steuber
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Patrick De Boever
- Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Nandu Goswami
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria.
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria.
- Integrative Health, Alma Mater Europaea Maribor, Maribor, Slovenia.
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
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Dorogovtsev VN, Yankevich DS, Gaydashev AE, Martyushev-Poklad AV, Podolskaya JA, Borisov IV, Grechko AV. Preclinical Orthostatic Abnormalities May Predict Early Increase in Vascular Stiffness in Different Age Groups: A Pilot Study. Diagnostics (Basel) 2023; 13:3243. [PMID: 37892064 PMCID: PMC10606479 DOI: 10.3390/diagnostics13203243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/06/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Clinical orthostatic hypotension (OH) and hypertension (OHT) are risk factors for arterial hypertension (AH) and cardiovascular diseases (CVD) and are associated with increased vascular stiffness. Preclinical OH and OHT are poorly understood. The main objective was to investigate preclinical orthostatic abnormalities and their association with increased vascular stiffness in different age groups of adults. A specially designed head-up tilt test standardized for hydrostatic column height was used to detect them. Three age groups of clinically healthy subjects were examined. In the group of young adults up to 30 years old, a significant predominance of orthostatic normotension (ONT) and an insignificant number of subjects with preclinical OH and OHT were found. In the age group over 45 years, compared to the group under 30 years, there was a twofold decrease in the proportion of individuals with ONT and a significant increase with preclinical OH and OHT. In all age groups, there was a significant orthostatic increase in vascular stiffness (as measured by the brachial-ankle pulse wave velocity (baPWV), which was recovered to the baseline level when returning to the supine position. Overall, subjects with preclinical OH and OHT had significantly higher baPWV values compared to those with ONT (p = 0.001 and p = 0.002, respectively), with all subjects having vascular stiffness values within normal age-related values.
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Affiliation(s)
- Victor N. Dorogovtsev
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
| | - Dmitry S. Yankevich
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
| | - Andrey E. Gaydashev
- Problem Scientific Research Laboratory, Smolensk State Medical University, 214019 Smolensk, Russia;
| | - Andrey V. Martyushev-Poklad
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
| | - Julia A. Podolskaya
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
| | - Ilya V. Borisov
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
| | - Andrey V. Grechko
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (D.S.Y.); (A.V.M.-P.); (J.A.P.); (A.V.G.)
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Goswami N. Compensatory hemodynamic changes in response to central hypovolemia in humans: lower body negative pressure: updates and perspectives. J Muscle Res Cell Motil 2023; 44:89-94. [PMID: 36380185 PMCID: PMC10329599 DOI: 10.1007/s10974-022-09635-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/19/2022] [Indexed: 11/16/2022]
Abstract
Central hypovolemia is accompanied by hemodynamic compensatory responses. Understanding the complex systemic compensatory responses to altered hemodynamic patterns during conditions of central hypovolemia-as induced by standing up and/or lower body negative pressure (LBNP)-in humans are important. LBNP has been widely used to understand the integrated physiological responses, which occur during sit to stand tests (orthostasis), different levels of hemorrhages (different levels of LBNP simulate different amount of blood loss) as well as a countermeasure against the cephalad fluid shifts which are seen during spaceflight. Additionally, LBNP application (used singly or together with head up tilt, HUT) is useful in understanding the physiology of orthostatic intolerance. The role seasonal variations in hormonal, autonomic and circulatory state play in LBNP-induced hemodynamic responses and LBNP tolerance as well as sex-based differences during central hypovolemia and the adaptations to exercise training have been investigated using LBNP. The data generated from LBNP studies have been useful in developing better models for prediction of orthostatic tolerance and/or for developing countermeasures. This review examines how LBNP application influences coagulatory parameters and outlines the effects of temperature changes on LBNP responses. Finally, the review outlines how LBNP can be used as innovative teaching tool and for developing research capacities and interests of medical students and students from other disciplines such as mathematics and computational biology.
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Affiliation(s)
- Nandu Goswami
- Division of Physiology, Gravitational Physiology and Medicine Research Unit, Otto Löwi Research Center of Vascular Biology, Inflammation, and Immunity, Medical University of Graz, Neue Stiftingtalstrasse 6, D-5, 8036, Graz, Austria.
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
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Kumar P, Das AK, Halder S. Statistical heart rate variability analysis for healthy person: Influence of gender and body posture. J Electrocardiol 2023; 79:81-88. [PMID: 37003104 DOI: 10.1016/j.jelectrocard.2023.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/19/2023] [Indexed: 03/29/2023]
Abstract
Short-term ECG-derived heart rate variability can assess autonomic function non-invasively. The purpose of this study is to investigate the influence of body posture and gender on parasympathetic-sympathetic balance by utilising electrocardiogram (ECG). A total of sixty participants including thirty males (95% CI: 23.34-26.32 years old) and thirty females (95% CI: 23.33-26.07 years old) voluntarily executed three sets of 5-min ECG recordings in supine, sitting and standing posture. A nonparametric Friedman test followed by Bonferroni post-hoc test was carried out to find the statistical differences between the group. A significant difference was observed for RR mean, low frequency (LF), high frequency (HF), ratio LF/HF and the ratio long term variability to short term variability (SD2/SD1) for p < 0.01 while respiration rate (Resp Rate), standard deviation of heart rate (STD_HR), long term variability (SD2), approximate entropy (ApEn), correlation dimension (CD) are non-significant (p > 0.01) for supine, sitting and standing. HRV indices such as standard deviation of NN (SDNN), HRV triangular index (HRVi), and triangular interpolation of NN interval (TINN) are statistically not significant for males but there are significant differences for females at a significance level 1%. Relative reliability and relatedness were evaluated through the interclass coefficient (ICC) and spearman correlation coefficient. The experimental results advocate that there is a posture-specific difference in HRV indices while the correlational studies suggest no such significant differences.
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6
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Controls of Central and Peripheral Blood Pressure and Hemorrhagic/Hypovolemic Shock. J Clin Med 2023; 12:jcm12031108. [PMID: 36769755 PMCID: PMC9917827 DOI: 10.3390/jcm12031108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
The pressure exerted on the heart and blood vessels because of blood flow is considered an essential parameter for cardiovascular function. It determines sufficient blood perfusion, and transportation of nutrition, oxygen, and other essential factors to every organ. Pressure in the primary arteries near the heart and the brain is known as central blood pressure (CBP), while that in the peripheral arteries is known as peripheral blood pressure (PBP). Usually, CBP and PBP are correlated; however, various types of shocks and cardiovascular disorders interfere with their regulation and differently affect the blood flow in vital and accessory organs. Therefore, understanding blood pressure in normal and disease conditions is essential for managing shock-related cardiovascular implications and improving treatment outcomes. In this review, we have described the control systems (neural, hormonal, osmotic, and cellular) of blood pressure and their regulation in hemorrhagic/hypovolemic shock using centhaquine (Lyfaquin®) as a resuscitative agent.
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Gąsior JS, Zamunér AR, Madeyska M, Tomik A, Niszczota C, Williams CA, Werner B. Heart Rate Variability in Individuals with Down Syndrome: A Scoping Review with Methodological Considerations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:941. [PMID: 36673696 PMCID: PMC9859252 DOI: 10.3390/ijerph20020941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/31/2022] [Accepted: 01/01/2023] [Indexed: 06/17/2023]
Abstract
Individuals with Down syndrome (DS) present similar heart rate variability (HRV) parameters at rest but different responses to selected movement maneuvers in comparison to individuals without DS, which indicates reduced vagal regulation. The present study undertakes a scoping review of research on HRV in individuals with DS, with special attention paid to the compliance of the studies with standards and methodological paper guidelines for HRV assessment and interpretation. A review was performed using PubMed, Web of Science and CINAHL databases to search for English language publications from 1996 to 2020 with the MESH terms "heart rate variability" and "down syndrome", with the additional inclusion criteria of including only human participants and empirical investigations. From 74 studies, 15 were included in the review. None of the reviewed studies met the recommendations laid out by the standards and guidelines for providing the acquisition of RR intervals and necessary details on HRV analysis. Since authors publishing papers on this research topic do not adhere to the prescribed standards and guidelines when constructing the methodology, results of the research papers on the topic are not directly comparable. Authors need to design the study methodology more robustly by following the aforementioned standards, guidelines and recommendations.
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Affiliation(s)
- Jakub S. Gąsior
- Department of Pediatric Cardiology and General Pediatrics, Medical University of Warsaw, 02-091 Warsaw, Poland
| | | | - Margaret Madeyska
- Pediatric Cardiology and General Pediatrics Clinic, Jan Polikarp Brudziński Pediatric Hospital, 02-091 Warsaw, Poland
| | - Anna Tomik
- Faculty of Medicine, Medical University of Warsaw, 02-091 Warsaw, Poland
| | - Cezary Niszczota
- Pediatric Cardiology and General Pediatrics Clinic, Jan Polikarp Brudziński Pediatric Hospital, 02-091 Warsaw, Poland
| | - Craig A. Williams
- Children’s Health & Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK
| | - Bożena Werner
- Department of Pediatric Cardiology and General Pediatrics, Medical University of Warsaw, 02-091 Warsaw, Poland
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Whittle RS, Keller N, Hall EA, Vellore HS, Stapleton LM, Findlay KH, Dunbar BJ, Diaz‐Artiles A. Gravitational Dose‐Response Curves for Acute Cardiovascular Hemodynamics and Autonomic Responses in a Tilt Paradigm. J Am Heart Assoc 2022; 11:e024175. [PMID: 35861832 PMCID: PMC9707822 DOI: 10.1161/jaha.121.024175] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
The cardiovascular system is strongly dependent on the gravitational environment. Gravitational changes cause mechanical fluid shifts and, in turn, autonomic effectors influence systemic circulation and cardiac control. We implemented a tilt paradigm to (1) investigate the acute hemodynamic response across a range of directions of the gravitational vector, and (2) to generate specific dose‐response relationships of this gravitational dependency.
Methods and Results
Twelve male subjects were tilted from 45° head‐up tilt to 45° head‐down tilt in 15° increments, in both supine and prone postures. We measured the steady‐state hemodynamic response in a range of variables including heart rate, stroke volume, cardiac output, oxygen consumption, total peripheral resistance, blood pressure, and autonomic indices derived from heart rate variability analysis. There is a strong gravitational dependence in almost all variables considered, with the exception of oxygen consumption, whereas systolic blood pressure remained controlled to within ≈3% across the tilt range. Hemodynamic responses are primarily driven by differential loading on the baroreflex receptors, combined with differences in venous return to the heart. Thorax compression in the prone position leads to reduced venous return and increased sympathetic nervous activity, raising heart rate, and systemic vascular resistance while lowering cardiac output and stroke volume.
Conclusions
Gravitational dose‐response curves generated from these data provide a comprehensive baseline from which to assess the efficacy of potential spaceflight countermeasures. Results also assist clinical management of terrestrial surgery in prone posture or head‐down tilt positions.
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Affiliation(s)
- Richard S. Whittle
- Department of Aerospace Engineering Texas A&M University College Station TX
| | - Nathan Keller
- Department of Health and Kinesiology Texas A&M University College Station TX
| | - Eric A. Hall
- Department of Biomedical Engineering Texas A&M University College Station TX
| | | | | | | | - Bonnie J. Dunbar
- Department of Aerospace Engineering Texas A&M University College Station TX
| | - Ana Diaz‐Artiles
- Department of Aerospace Engineering Texas A&M University College Station TX
- Department of Health and Kinesiology Texas A&M University College Station TX
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Analysis of Short-Term Heart Rate Asymmetry in High-Performance Athletes and Non-Athletes. Symmetry (Basel) 2022. [DOI: 10.3390/sym14061229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Heart rate asymmetry (HRA) refers to how asymmetrically the acceleration and deceleration patterns in heartbeat fluctuations are distributed. There is limited evidence regarding HRA changes in athletes and their association with autonomic regulation. This study aimed to compare the short-term HRA of high-performance athletes and non-athletes during an autonomic function test by calculating relevant HRA measures. This exploratory study obtained beat-to-beat RR interval time series from 15 high-performance athletes and 12 non-athletes during a standardized autonomic function test. This test includes rest, postural change, controlled respiration, prolonged orthostatism, exercise, and recovery phases. The following HRA parameters were computed from the RR time series for both groups: asymmetric spread index (ASI), slope index (SI), Porta’s index (PI), Guzik’s index (GI), and Ehlers’ index (EI). We found significant differences (p < 0.01) in the mean value of several HRA parameters between athletes and non-athletes and across the autonomic function test phases, mainly in postural change and recovery phases. Our results indicate that high-performance athletes manifest a higher number and magnitude of cardiac decelerations than non-athletes after an orthostatic challenge, as indicated by GI and EI. In addition, lower HRA was found in athletes in the recovery phase than in non-athletes, as indicated by ASI.
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Ballambat RP, Zuber M, Khader SMA, Ayachit A, Ahmad KAB, Vedula RR, Kamath SG, Shuaib IL. Influence of postural changes on haemodynamics in internal carotid artery bifurcation aneurysm using numerical methods. Vis Comput Ind Biomed Art 2022; 5:11. [PMID: 35394268 PMCID: PMC8993999 DOI: 10.1186/s42492-022-00107-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 03/14/2022] [Indexed: 01/09/2023] Open
Abstract
Cerebral intracranial aneurysms are serious problems that can lead to stroke, coma, and even death. The effect of blood flow on cerebral aneurysms and their relationship with rupture are unknown. In addition, postural changes and their relevance to haemodynamics of blood flow are difficult to measure in vivo using clinical imaging alone. Computational simulations investigating the detailed haemodynamics in cerebral aneurysms have been developed in recent times not only to understand the progression and rupture but also for clinical evaluation and treatment. In the present study, the haemodynamics of a patient-specific case of a large aneurysm on the left side internal carotid bifurcation (LICA) and no aneurysm on the right side internal carotid bifurcation (RICA) was investigated. The simulation of these patient-specific models using fluid–structure interaction provides a valuable comparison of flow behavior between normal and aneurysm models. The influences of postural changes were investigated during standing, sleeping, and head-down (HD) position. Significant changes in flow were observed during the HD position and quit high arterial blood pressure in the internal carotid artery (ICA) aneurysm model was established when compared to the normal ICA model. The velocity increased abruptly during the HD position by more than four times (LICA and RICA) and wall shear stress by four times (LICA) to ten times (RICA). The complex spiral flow and higher pressures prevailing within the dome increase the risk of aneurysm rupture.
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Affiliation(s)
- Raghuvir Pai Ballambat
- Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Mohammad Zuber
- Department of Aeronautical and Automobile Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Shah Mohammed Abdul Khader
- Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India.
| | - Anurag Ayachit
- Department of Radiology and Imaging, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Kamarul Arifin Bin Ahmad
- Department of Aerospace Engineering, Faculty of Engineering, Universitist Putra Malaysia, 43499, Kuala Lumpur, Malaysia
| | - Rajanikanth Rao Vedula
- Department of Radiology and Imaging, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Sevagur Ganesh Kamath
- Department of Cardio-Vascular and Thoracic Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Ibrahim Lutfi Shuaib
- Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, George Town, Malaysia
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Hussain S, Raza Z, Kumar TVV, Goswami N. Diagnosing Neurally Mediated Syncope Using Classification Techniques. J Clin Med 2021; 10:jcm10215016. [PMID: 34768538 PMCID: PMC8584937 DOI: 10.3390/jcm10215016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 11/16/2022] Open
Abstract
Syncope is a medical condition resulting in the spontaneous transient loss of consciousness and postural tone with spontaneous recovery. The diagnosis of syncope is a challenging task, as similar types of symptoms are observed in seizures, vertigo, stroke, coma, etc. The advent of Healthcare 4.0, which facilitates the usage of artificial intelligence and big data, has been widely used for diagnosing various diseases based on past historical data. In this paper, classification-based machine learning is used to diagnose syncope based on data collected through a head-up tilt test carried out in a purely clinical setting. This work is concerned with the use of classification techniques for diagnosing neurally mediated syncope triggered by a number of neurocardiogenic or cardiac-related factors. Experimental results show the effectiveness of using classification-based machine learning techniques for an early diagnosis and proactive treatment of neurally mediated syncope.
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Affiliation(s)
- Shahadat Hussain
- School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (S.H.); (T.V.V.K.)
| | - Zahid Raza
- School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (S.H.); (T.V.V.K.)
- Correspondence:
| | - T V Vijay Kumar
- School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (S.H.); (T.V.V.K.)
| | - Nandu Goswami
- Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, 8036 Graz, Austria;
- Department of Health Sciences, Alma Mater Europea Maribor, 2000 Maribor, Slovenia
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12
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Hussain S, Raza Z, Giacomini G, Goswami N. Support Vector Machine-Based Classification of Vasovagal Syncope Using Head-Up Tilt Test. BIOLOGY 2021; 10:1029. [PMID: 34681130 PMCID: PMC8533587 DOI: 10.3390/biology10101029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 12/12/2022]
Abstract
Syncope is the medical condition of loss of consciousness triggered by the momentary cessation of blood flow to the brain. Machine learning techniques have been established to be very effective way to address such problems, where a class label is predicted for given input data. This work presents a Support Vector Machine (SVM) based classification of neuro-mediated syncope evaluated using train-test-split and K-fold cross-validation methods using the patient's physiological data collected through the Head-up Tilt Test in pure clinical settings. The performance of the model has been analyzed over standard statistical performance indices. The experimental results prove the effectiveness of using SVM-based classification for the proactive diagnosis of syncope.
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Affiliation(s)
- Shahadat Hussain
- School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi 110067, India;
| | - Zahid Raza
- School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi 110067, India;
| | | | - Nandu Goswami
- Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, 8036 Graz, Austria;
- Alma Mater Europaea, 17 2000 Maribor, Slovenia
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Ferreira FC, Vaz Padilha MCS, Tobadini E, Carandina A, Montano N, Soares PPDS, Rodrigues GD. The interplay between heated environment and active standing test on cardiovascular autonomic control in healthy individuals. Physiol Meas 2021; 42. [PMID: 34261052 DOI: 10.1088/1361-6579/ac1497] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 07/14/2021] [Indexed: 01/03/2023]
Abstract
Objective.To investigate the interplay between active standing and heat stress on cardiovascular autonomic modulation in healthy individuals.Approach.Blood pressure (BP) and ECG were continuously recorded during 30 min in supine (SUP) and 6 min in orthostatic position (ORT) under thermal reference (TC; ∼24 °C) or heated environment (HOT; ∼36 °C) conditions, in a randomized order. All data collection was performed during the winter and spring seasons when typical outdoor temperatures are ∼23 °C. Spectral analysis was employed by the autoregressive model of R-R and systolic blood pressure (SBP) time series and defined, within each band, in low (LF, 0.04 to 0.15 Hz) and high (0.15-0.40 Hz) frequencies. The indices of cardiac sympathetic (LF) and cardiac parasympathetic (HF) were normalized (nu) dividing each band power by the total power subtracted the very-low component (<0.04 Hz), obtaining the cardiac autonomic balance (LF/HF) modulation. The gain of the relationship between SBP and R-R variabilities within the LF band was utilized for analysis of spontaneous baroreflex sensitivity (alpha index;αLF). Nonlinear analysis was employed through symbolic dynamics of R-R, which provided the percentage of sequences of three heart periods without changes in R-R interval (0V%; cardiac sympathetic modulation) and two significant variations (2UV% and 2LV%; cardiac vagal modulation).Main results.HOT increased 0V% and HR, and decreasedαLF and 2UV% during SUP compared to TC. During ORT, HOT provokes a greater increment on HR, LF/HF and 0V%, indexes compared to ORT under TC.Significance.At rest, heat stress influences both autonomic branches, increasing sympathetic and decreasing vagal modulation and spontaneous baroreflex sensitivity. The augmented HR during active standing under heat stress seems to be mediated by a greater increment in cardiac sympathetic modulation, showing an interplay between gravitational and thermal stimulus.
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Affiliation(s)
- Felipe Castro Ferreira
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Brazil
| | | | - Eleonora Tobadini
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, I-20122 Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, I-20122 Milan, Italy
| | - Angelica Carandina
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, I-20122 Milan, Italy
| | - Nicola Montano
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, I-20122 Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, I-20122 Milan, Italy
| | - Pedro Paulo da Silva Soares
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Brazil
| | - Gabriel Dias Rodrigues
- Laboratory of Experimental and Applied Exercise Physiology, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Brazil.,Department of Clinical Sciences and Community Health, University of Milan, I-20122 Milan, Italy
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14
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Brix B, White O, Ure C, Apich G, Simon P, Roessler A, Goswami N. Hemodynamic Responses in Lower Limb Lymphedema Patients Undergoing Physical Therapy. BIOLOGY 2021; 10:biology10070642. [PMID: 34356497 PMCID: PMC8301048 DOI: 10.3390/biology10070642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Lymphedema arises due to a malfunction of the lymphatic system, leading to extensive tissue swelling. Complete decongestive therapy (CDT), which is a physical therapy lasting for 3 weeks and includes manual lymphatic drainages (MLD), leads to fluid mobilization and increases in plasma volume. Here, we investigated hemodynamic responses induced by these fluid shifts due to CDT and MLD. METHODS Hemodynamic parameters were assessed continuously during a sit-to-stand test (5 min baseline, 5 min of standing, and 5 min of recovery). This intervention was repeated on days 1, 2, 7, 14, and 21 of CDT, before and after MLD. Volume regulatory hormones were assessed in plasma samples. RESULTS A total number of 13 patients took part in this investigation. Resting diastolic blood pressure significantly decreased over three weeks of CDT (p = 0.048). No changes in baseline values were shown due to MLD. However, MLD led to a significant decrease in heart rate during orthostatic loading over all epochs on therapy day 14, as well as day 21. Volume regulatory hormones did not show changes over lymphedema therapy. CONCLUSION We did not observe any signs of orthostatic hypotension at rest, as well as during to CDT, indicating that lymphedema patients do not display an elevated risk of orthostatic intolerance. Although baseline hemodynamics were not affected, MLD has shown to have potential beneficial effects on hemodynamic responses to a sit-to-stand test in patients undergoing lymphedema therapy.
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Affiliation(s)
- Bianca Brix
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria; (B.B.); (P.S.); (A.R.)
| | - Olivier White
- Unit 1093, Cognition, Action and Sensorimotor Plasticity, Institut National de la Santé et de la Recherche Médicale, 21000 Dijon, France;
| | - Christian Ure
- Clinical Center for Lymphatic Disorders, Wolfsberg State Hospital, KABEG, 9400 Wolfsberg, Austria; (C.U.); (G.A.)
| | - Gert Apich
- Clinical Center for Lymphatic Disorders, Wolfsberg State Hospital, KABEG, 9400 Wolfsberg, Austria; (C.U.); (G.A.)
- Physical Medicine and General Rehabilitation, KABEG, Wolfsberg Site, 9400 Wolfsberg, Austria
| | - Paul Simon
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria; (B.B.); (P.S.); (A.R.)
| | - Andreas Roessler
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria; (B.B.); (P.S.); (A.R.)
| | - Nandu Goswami
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Otto Loewi Research Center, Medical University of Graz, 8010 Graz, Austria; (B.B.); (P.S.); (A.R.)
- Correspondence:
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15
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Alhakak AS, Teerlink JR, Lindenfeld J, Böhm M, Rosano GMC, Biering-Sørensen T. The significance of left ventricular ejection time in heart failure with reduced ejection fraction. Eur J Heart Fail 2021; 23:541-551. [PMID: 33590579 DOI: 10.1002/ejhf.2125] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/25/2021] [Accepted: 02/10/2021] [Indexed: 01/10/2023] Open
Abstract
Left ventricular ejection time (LVET) is defined as the time interval from aortic valve opening to aortic valve closure, and is the phase of systole during which the left ventricle ejects blood into the aorta. LVET has been used for several decades to assess left ventricular function and contractility. However, there is a recent interest in LVET as a measure of therapeutic action for novel drugs in patients with heart failure with reduced ejection fraction (HFrEF), since LVET is shortened in these patients. This review provides an overview of the available information on LVET including methods of measuring LVET, mechanistic understanding of LVET, association of LVET with outcomes, mechanisms behind shortened LVET in HFrEF and the potential implications of drugs that affect and normalize LVET.
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Affiliation(s)
- Alia S Alhakak
- Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - John R Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of Medicine, University of California San Francisco, San Francisco, CA, USA
| | | | - Michael Böhm
- Department of Internal Medicine, Klinik für Innere Medizin III, Universitätsklinikum Des Saarlandes, Saarland University, Homburg/Saar, Germany
| | | | - Tor Biering-Sørensen
- Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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16
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Dorogovtsev VN, Yankevich DS, Goswami N. Effects of an Innovative Head-Up Tilt Protocol on Blood Pressure and Arterial Stiffness Changes. J Clin Med 2021; 10:1198. [PMID: 33805654 PMCID: PMC7998828 DOI: 10.3390/jcm10061198] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/26/2021] [Accepted: 03/09/2021] [Indexed: 11/16/2022] Open
Abstract
The objective of our study was to identify blood pressure (BP) and pulse wave velocity (PWV) changes during orthostatic loading, using a new the head-up tilt test (HUTT), which incorporates the usage of a standardized hydrostatic column height. METHODS 40 healthy subjects 20-32 years performed HUTT, which was standardized to a height of the hydrostatic column at 133 cm. Exposure time was 10 min in each of 3 positions: horizontal supine 1, HUTT, and horizontal supine 2. The individual tilt up angle made it possible to set the standard value of the hydrostatic column. Hemodynamic parameters were recorded beat to beat using "Task Force Monitor 3040 i", pulse-wave velocity (PWV) was measured with a sphygmograph-sphygmomanometer VaSera VS1500N. RESULTS Orthostatic loading caused a significant increase in heart rate (HR) and a decrease in stroke volume (SV) (p < 0.05) but no significant reductions in cardiac output, changes in total vascular resistance (TVR), or BP. An analysis of personalized data on systolic blood pressure (SBP) changes in tilt up position as compared to horizontal position (ΔSBP) revealed non-significant changes in this index in 48% of subjects (orthostatic normotension group), in 32% there was a significant decrease in it (orthostatic hypotension group) and in 20% there was a significant increase in it (orthostatic hypertension group). These orthostatic changes were not accompanied by any clinical symptoms and/or syncope. During HUTT, all subjects had in the PWV a significant increase of approximately 27% (p < 0.001). CONCLUSION The new test protocol involving HUTT standardized to a height of hydrostatic column at 133 cm causes typical hemodynamics responses during orthostatic loading. Individual analysis of the subjects revealed subclinical orthostatic disorders (OSD) in up to 52% of the test persons. During HUTT, all test subjects showed a significant increase in PWV. The new innovative HUTT protocol can be applied in multi-center studies in healthy subjects to detect preclinical forms of orthostatic disorders under standard gravity load conditions.
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Affiliation(s)
- Victor N. Dorogovtsev
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (V.N.D.); (D.S.Y.)
| | - Dmitry S. Yankevich
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, 107031 Moscow, Russia; (V.N.D.); (D.S.Y.)
| | - Nandu Goswami
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Otto Loewi Research Center, Medical University of Graz, 3810 Graz, Austria
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Hossein A, Rabineau J, Gorlier D, Pinki F, van de Borne P, Nonclercq A, Migeotte PF. Effects of acquisition device, sampling rate, and record length on kinocardiography during position-induced haemodynamic changes. Biomed Eng Online 2021; 20:3. [PMID: 33407507 PMCID: PMC7788803 DOI: 10.1186/s12938-020-00837-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/10/2020] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Kinocardiography (KCG) is a promising new technique used to monitor cardiac mechanical function remotely. KCG is based on ballistocardiography (BCG) and seismocardiography (SCG), and measures 12 degrees-of-freedom (DOF) of body motion produced by myocardial contraction and blood flow through the cardiac chambers and major vessels. RESULTS The integral of kinetic energy ([Formula: see text]) obtained from the linear and rotational SCG/BCG signals was computed over each dimension over the cardiac cycle, and used as a marker of cardiac mechanical function. We tested the hypotheses that KCG metrics can be acquired using different sensors, and at 50 Hz. We also tested the effect of record length on the ensemble average on which the metrics were computed. Twelve healthy males were tested in the supine, head-down tilt, and head-up tilt positions to expand the haemodynamic states on which the validation was performed. CONCLUSIONS KCG metrics computed on 50 Hz and 1 kHz SCG/BCG signals were very similar. Most of the metrics were highly similar when computed on different sensors, and with less than 5% of error when computed on record length longer than 60 s. These results suggest that KCG may be a robust and non-invasive method to monitor cardiac inotropic activity. Trial registration Clinicaltrials.gov, NCT03107351. Registered 11 April 2017, https://clinicaltrials.gov/ct2/show/NCT03107351?term=NCT03107351&draw=2&rank=1 .
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Affiliation(s)
- Amin Hossein
- LPHYS, Université Libre de Bruxelles, Brussels, Belgium.
- BEAMS, Université Libre de Bruxelles, Brussels, Belgium.
| | | | | | - Farhana Pinki
- LPHYS, Université Libre de Bruxelles, Brussels, Belgium
| | - Philippe van de Borne
- Department of Cardiology, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
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Yuan Y, Mu JJ, Chu C, Zheng WL, Wang Y, Hu JW, Ma Q, Wang KK, Yan Y, Liao YY, Chen C. Predictive Role of Child-To-Adult Blood Pressure Trajectories for Incident Metabolic Syndrome: 30-Year Hanzhong Adolescent Hypertension Study. Endocr Pract 2020; 27:433-442. [PMID: 33840450 DOI: 10.1016/j.eprac.2020.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 08/06/2020] [Accepted: 09/04/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The relationship between child-to-adult blood pressure (BP) trajectories and metabolic syndrome (MetS) is unknown. We aimed to determine the predictive role of BP trajectories for incident MetS and its components. METHODS The prospective Hanzhong Adolescent Hypertension study began in 1987 and included 2692 participants free of MetS at baseline with at least 3 BP measurements available from 1987 to 2017. RESULTS The systolic BP (SBP) trajectory patterns were grouped as normal (class 1, 18.7%), high normal (class 2, 60.3%), prehypertensive (class 3, 13.1%), stage 1 hypertensive (class 4, 5.7%), and stage 2 hypertensive (class 5, 2.2%). Compared with those in the normal group, individuals in classes 2 to 5 had significantly higher risks of MetS (all Ps < .05), and those with hypertension had more than an 8-fold higher risk of MetS (both P < .05). The fully adjusted risk ratios (RRs) of central obesity increased significantly in a stepwise manner as the SBP trajectory group increased from class 1 to class 5 (P < .05). Compared with those with a normal SBP trajectory, participants in the prehypertensive group and stage 1 and stage 2 hypertensive groups had significantly higher RRs for high-risk triglycerides after full adjustment (RR = 1.89 [1.22-2.94]; RR = 3.61 [2.16-6.02]; and RR = 3.22 [1.52-6.84], respectively). CONCLUSION Our study suggests that BP trajectories are predictive of incident MetS outcomes. Early detection of hypertension or modest elevations in BP is crucial. The stage of hypertension based on SBP level showed a greater association with central obesity.
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Affiliation(s)
- Yue Yuan
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Jian-Jun Mu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China.
| | - Chao Chu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Wen-Ling Zheng
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Yang Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Jia-Wen Hu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Qiong Ma
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Ke-Ke Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Yu Yan
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Yue-Yuan Liao
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
| | - Chen Chen
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China; Key Laboratory of Molecular Cardiology of Shaanxi Province, Xi'an, China
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Goswami N, Abulafia C, Vigo D, Moser M, Cornelissen G, Cardinali D. Falls Risk, Circadian Rhythms and Melatonin: Current Perspectives. Clin Interv Aging 2020; 15:2165-2174. [PMID: 33204081 PMCID: PMC7666981 DOI: 10.2147/cia.s283342] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/03/2020] [Indexed: 01/31/2023] Open
Abstract
Aging is associated with weakening of the circadian system. The circadian amplitude of most physiological variables is reduced, while the circadian phase becomes more labile and tends to occur earlier with advancing age. As the incidence of falls in older persons could follow circadian variations, a better understanding of conditions in which falls occur can lead to the implementation of countermeasures (such as adjusting the scheduling of hospital staff, or changing the timing of anti-hypertensive medication if falls are related to undesirable circadian patterns of blood pressure and/or heart rate). This includes knowing the times of the day, days of the week, and times of the year when falls are more likely to occur at home or in the hospital. Additionally, the links between aging processes and factors associated with an increased risk of developing autonomic dysfunction are well established. A strong association between heart rate variability indexes and aging has been shown. Circadian rhythms of autonomous nervous system activity may play important role for maintenance of orthostatic tolerance. Whether one is concerned with disease prediction and prevention or maintenance of healthy aging, the study of circadian rhythms and the broader time structure underlying physiopathology is helpful in terms of screening, early diagnosis and prognosis, as well as the timely institution of prophylactic and/or palliative/curative treatment. Timing the administration of such treatment as a function of circadian (and other) rhythms also could lead to reduction of falls in older persons. Finally, a prominent circadian rhythm characterizes melatonin, which peaks during the night. The circadian amplitude of melatonin decreases as a function of age, raising the questions whether such a decrease in the circadian amplitude of melatonin relates to a higher risk of falls and, if so, whether melatonin supplementation may be an effective countermeasure. This narrative review assesses the relationships between fall risk and the potential role circadian rhythms and melatonin play in mitigating this risk. We aim to provide healthcare workers adequate information about fall risk in older persons, including the potential role of the circadian rhythms and/or melatonin, as well as to lay foundations for future fall prevention interventional studies.
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Affiliation(s)
- Nandu Goswami
- Physiology Division, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, Graz, Austria
| | - Carolina Abulafia
- Institute for Biomedical Research (BIOMED), Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Autonomous City of Buenos Aires, Argentina
| | - Daniel Vigo
- Institute for Biomedical Research (BIOMED), Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Autonomous City of Buenos Aires, Argentina
| | - Maximilian Moser
- Physiology Division, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, Graz, Austria
| | | | - Daniel Cardinali
- Institute for Biomedical Research (BIOMED), Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Autonomous City of Buenos Aires, Argentina
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20
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Laing C, Green DA, Mulder E, Hinghofer-Szalkay H, Blaber AP, Rittweger J, Goswami N. Effect of novel short-arm human centrifugation-induced gravitational gradients upon cardiovascular responses, cerebral perfusion and g-tolerance. J Physiol 2020; 598:4237-4249. [PMID: 32715482 PMCID: PMC7589294 DOI: 10.1113/jp273615] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/08/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The aim of this study was to determine the effect of rotational axis position (RAP and thus g-gradient) during short-arm human centrifugation (SAHC) upon cardiovascular responses, cerebral perfusion and g-tolerance. In 10 male and 10 female participants, 10 min passive SAHC runs were performed with the RAP above the head (P1), at the apex of the head (P2), or at heart level (P3), with foot-level Gz at 1.0 g, 1.7 g and 2.4 g. We hypothesized that movement of the RAP from above the head (the conventional position) towards the heart might reduce central hypovolaemia, limit cardiovascular responses, aid cerebral perfusion, and thus promote g-tolerance. Moving the RAP footward towards the heart decreased the cerebral tissue saturation index, calf circumference and heart rate responses to SAHC, thereby promoting g-tolerance. Our results also suggest that RAP, and thus g-gradient, warrants further investigation as it may support use as a holistic spaceflight countermeasure. ABSTRACT Artificial gravity (AG) through short-arm human centrifugation (SAHC) has been proposed as a holistic spaceflight countermeasure. Movement of the rotational axis position (RAP) from above the head towards the heart may reduce central hypovolaemia, aid cerebral perfusion, and thus promote g-tolerance. This study determined the effect of RAP upon cardiovascular responses, peripheral blood displacement (i.e. central hypovolaemia), cerebral perfusion and g-tolerance, and their inter-relationships. Twenty (10 male) healthy participants (26.2 ± 4.0 years) underwent nine (following a familiarization run) randomized 10 min passive SAHC runs with RAP set above the head (P1), at the apex of the head (P2), or at heart level (P3) with foot-level Gz at 1.0 g, 1.7 g and 2.4 g. Cerebral tissue saturation index (cTSI, cerebral perfusion surrogate), calf circumference (CC, central hypovolaemia), heart rate (HR) and digital heart-level mean arterial blood pressure (MAP) were continuously recorded, in addition to incidence of pre-syncopal symptoms (PSS). ΔCC and ΔHR increases were attenuated from P1 to P3 (ΔCC: 5.46 ± 0.54 mm to 2.23 ± 0.42 mm; ΔHR: 50 ± 4 bpm to 8 ± 2 bpm, P < 0.05). In addition, ΔcTSI decrements were also attenuated (ΔcTSI: -2.85 ± 0.48% to -0.95 ± 0.34%, P < 0.05) and PSS incidence lower in P3 than P1 (P < 0.05). A positive linear relationship was observed between ΔCC and ΔHR with increasing +Gz, and a negative relationship between ΔCC and ΔcTSI, both independent of RAP. Our data suggest that movement of RAP towards the heart (reduced g-gradient), independent of foot-level Gz, leads to improved g-tolerance. Further investigations are required to assess the effect of differential baroreceptor feedback (i.e. aortic-carotid g-gradient).
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Affiliation(s)
- Charles Laing
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.,King's College London, Centre for Human and Applied Physiological Sciences (CHAPS), London, UK
| | - David A Green
- King's College London, Centre for Human and Applied Physiological Sciences (CHAPS), London, UK.,Space Medicine Team, HRE-OM, European Astronaut Centre, European Space Agency, Cologne, Germany.,KBR, Wyle Laboratories GmbH, Cologne, Germany
| | - Edwin Mulder
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Helmut Hinghofer-Szalkay
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Medical University of Graz, Austria
| | - Andrew P Blaber
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Joern Rittweger
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.,Department of Paediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
| | - Nandu Goswami
- Gravitational Physiology and Medicine Research Unit, Division of Physiology, Medical University of Graz, Austria
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Cardio-postural interactions and muscle-pump baroreflex are severely impacted by 60-day bedrest immobilization. Sci Rep 2020; 10:12042. [PMID: 32694819 PMCID: PMC7374578 DOI: 10.1038/s41598-020-68962-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 06/26/2020] [Indexed: 02/07/2023] Open
Abstract
To understand fundamental mechanisms associated with post-flight orthostatic intolerance we investigated the interaction between the cardiovascular and postural functions before and after 60 days of head down bedrest (HDBR). Twenty healthy young males (35.0 ± 1.7 years) were subjected to 60-day HDBR at 6˚ to simulate spaceflight-induced fluid shifts. A supine-to-stand (STS) test was conducted to evaluate cardio-postural control before and after (R) HDBR while an assessment of cardiovascular function was performed during HDBR. Beat-to-beat heart period, systolic blood pressure, and electromyography impulses were derived for wavelet transform coherence and causality analyses of the cardio-postural control and used to assess changes in the muscle-pump baroreflex. During quiet stand of the STS test, compared to baseline, heart rate was 50% higher on the day of exit from bedrest (R0) and 20% higher eight days later (R8). There was a 50% increase in deoxygenated hemoglobin on R0 and R8. Leg muscle activity reduced, and postural sway increased after HDBR. Causality of the muscle-pump baroreflex was reduced on R0 (0.73 ± 0.2) compared to baseline (0.87 ± 0.2) with complete recovery by R8. The muscle-pump baroreflex also had decreased gain and fraction time active following HDBR. Overall, our data show a significantly impaired muscle-pump baroreflex following bedrest.
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Kostic M, Gordon P, Monsalve P, Jang H, Lam BL, Guy J, McSoley J, Vazquez L, Hodapp E, Porciatti V. Non-invasive Assessment of Central Retinal Artery Pressure: Age and Posture-dependent Changes. Curr Eye Res 2020; 46:135-139. [PMID: 32441142 DOI: 10.1080/02713683.2020.1772833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Purpose: Assessment of Ocular Perfusion Pressure (OPP) requires estimation of the Mean Central Retinal Artery Pressure (MCRAP) [OPP = MCRAP-IOP]. In a seated position, MCRAP is currently estimated as 2/3 of the Mean Arterial Pressure (MAP) to account for the hydrostatic reduction of MAP at eye level. We tested a surrogate method for direct MCRAP assessment by measuring MAP with Arm-Up and cuff at eye level (AUMAP) at different postures and ages. Methods: MAP and AUMAP were assessed in a mixed population of 136 subjects (mean age 44 ± 17.39 years) including healthy participants (N = 30) and patients with optic neuropathies (Glaucoma suspects, N = 14; Open-Angle Glaucoma, N = 26, LHON, N = 19; MS, N = 47) not expected to alter systemic blood pressure. None of the subjects had history of carotid stenosis or pharmacological treatment to regulate blood pressure. AUMAP was also tested in two subgroups in supine (N = 42) and -10° Head Down body Tilt position (HDT, N = 46). Results: In the seated position, both 2/3MAP and AUMAP increased with increasing age, however with steeper (2x) slope for AUMAP (P < .0001). With decreasing angle of body tilt, AUMAP increased while MAP decreased. The mean AUMAP/MAP ratio (posture coefficient) was, seated, 0.73 (SE 0.003); supine, 0.90 (SE 0.005); HDT, 0.97 (SE 0.005). In the seated position only, the AUMAP/MAP ratio significantly increased with age (P < .0001). Mean posture coefficients obtained with AUMAP were in the range of those based on either direct ophthalmodynamometric measurements or hydrostatic estimations. Conclusions: Surrogate measurement of MCRAP in individual subjects is feasible using the simple AUMAP approach that provides a straightforward estimation of OPP (OPP = AUMAP - IOP) at different body postures. The standard method OPP = 2/3*MAP-IOP in the seated posture underestimates OPP at older ages. Clinical estimation of OPP would benefit from the use of AUMAP, in particular for head-down postures.
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Affiliation(s)
- Maja Kostic
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Phillip Gordon
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Pedro Monsalve
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Hong Jang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Byron L Lam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - John Guy
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - John McSoley
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Luis Vazquez
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Elizabeth Hodapp
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine , Miami, FL, USA
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Gąsior JS, Zamunér AR, Silva LEV, Williams CA, Baranowski R, Sacha J, Machura P, Kochman W, Werner B. Heart Rate Variability in Children and Adolescents with Cerebral Palsy-A Systematic Literature Review. J Clin Med 2020; 9:jcm9041141. [PMID: 32316278 PMCID: PMC7230809 DOI: 10.3390/jcm9041141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/04/2020] [Accepted: 04/13/2020] [Indexed: 12/14/2022] Open
Abstract
Cardiac autonomic dysfunction has been reported in patients with cerebral palsy (CP). The aim of this study was to assess the existing literature on heart rate variability (HRV) in pediatric patients with CP and a special attention was paid to the compliance of the studies with the current HRV assessment and interpretation guidelines. A systematic review was performed in PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases searched for English language publications from 1996 to 2019 using Medical Subject Headings (MeSH) terms “heart rate variability” and “cerebral palsy” in conjunction with additional inclusion criteria: studies limited to humans in the age range of 0–18 years and empirical investigations. Out of 47 studies, 12 were included in the review. Pediatric patients with CP presented a significantly higher resting heart rate and reduced HRV, different autonomic responses to movement stimuli compared to children with normal development, but also reduced HRV parameters in the children dependent on adult assistance for mobility compared to those generally independent. None of the included studies contained the necessary details concerning RR intervals acquisition and HRV measurements as recommended by the guidelines. Authors of HRV studies should follow the methodological guidelines and recommendations on HRV measurement, because such an approach may allow a direct comparison of their results.
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Affiliation(s)
- Jakub S. Gąsior
- Faculty of Medical Sciences and Health Sciences, Kazimierz Pulaski University of Technology and Humanities, 26-600 Radom, Poland
- Correspondence: ; Tel.: +48-793-199-222
| | | | - Luiz Eduardo Virgilio Silva
- Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil;
| | - Craig A. Williams
- Children’s Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St Luke’s Campus, Exeter EX1 2LU, UK;
| | - Rafał Baranowski
- Department of Heart Rhythm Disorders, National Institute of Cardiology, 04-628 Warsaw, Poland;
| | - Jerzy Sacha
- Faculty of Physical Education and Physiotherapy, Opole University of Technology, 45-758 Opole, Poland;
- Department of Cardiology, University Hospital in Opole, University of Opole, 45-401 Opole, Poland
| | - Paulina Machura
- Department of Gynaecological Endocrinology, Medical University of Warsaw, 00-950 Warsaw, Poland;
| | - Wacław Kochman
- Clinical Department of Cardiology at Bielanski Hospital, National Institute of Cardiology, 01-809 Warsaw, Poland;
| | - Bożena Werner
- Department of Pediatric Cardiology and General Pediatrics, Medical University of Warsaw, 02-091 Warsaw, Poland;
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Pizzey FK, Tourula E, Pearson J. Tolerance to Central Hypovolemia Is Greater Following Caffeinated Coffee Consumption in Habituated Users. Front Physiol 2020; 11:50. [PMID: 32116762 PMCID: PMC7013032 DOI: 10.3389/fphys.2020.00050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/21/2020] [Indexed: 11/13/2022] Open
Abstract
We investigated the influence of caffeinated coffee consumption on cardiovascular responses and tolerance to central hypovolemia in individuals habituated to caffeine. Thirteen participants completed three trials, consuming caffeinated coffee, decaffeinated coffee or water before exposure to central hypovolemia via lower body negative pressure (LBNP) to pre syncope. Tolerance to central hypovolemia was quantified as cumulative stress index (CSI: LBNP level multiplied by time; mmHg × min). Prior to the consumption of caffeinated coffee, decaffeinated coffee, and water, heart rate (HR: 62 ± 10, 63 ± 9 and 61 ± 8 BPM, respectively), stroke volume (SV: 103 ± 23, 103 ± 17 and 102 ± 18 mL/beat, respectively), and total peripheral resistance (TPR: 14.2 ± 3.0, 14.0 ± 3.0, and 14.3 ± 2.7 mmHg/L/min, respectively), were not different between trials (all P > 0.05). Mean arterial pressure (MAP) increased following consumption of all drinks (Post Drink) (Caffeinated coffee: from 86 ± 8 to 97 ± 7; Decaffeinated coffee: from 88 ± 10 to 94 ± 7; and Water: from 87 ± 10 to 96 ± 6 mmHg; all P = 0.0001) but was not different between trials (P = 0.247). During LBNP, HR increased (P = 0.000) while SV decreased (P = 0.000) relative to post drink values and TPR as unchanged (P = 0.109). HR, SV, and TPR were not different between trials (all P > 0.05). MAP decreased at pre syncope in all trials (60 ± 5, 60 ± 7, and 61 ± 6 mmHg; P < 0.001). LBNP tolerance was greater following caffeinated coffee (914 ± 309 mmHg × min) relative to decaffeinated coffee and water (723 ± 336 and 769 ± 337 mmHg × min, respectively, both P < 0.05). Tolerance to central hypovolemia was greater following consumption of caffeinated coffee in habituated users.
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Affiliation(s)
- Faith K. Pizzey
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
- School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Erica Tourula
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - James Pearson
- Department of Human Physiology and Nutrition, University of Colorado Colorado Springs, Colorado Springs, CO, United States
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25
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The effects of varying gravito-inertial stressors on grip strength and hemodynamic responses in men and women. Eur J Appl Physiol 2019; 119:951-960. [PMID: 30730002 PMCID: PMC6422992 DOI: 10.1007/s00421-019-04084-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/19/2019] [Indexed: 12/16/2022]
Abstract
Purpose The body behaves as a global system with many interconnected subsystems. While the effects of a gravitational change on body responses have been extensively studied in isolation, we are not aware of any study that has examined these two types of body responses concurrently. Here, we examined how the cognitive and cardiovascular systems respond during application of varying gravito-inertial stressors in men and women. Methods Ten men and nine women underwent three 5-min centrifugation sessions (2.4 g at the feet, 1.5 g at the heart) in which participants rhythmically moved a hand-held object for 20 s. Grip force and hemodynamic responses were continuously measured during centrifugation and rest periods. Result Men optimized the modulation between grip force and the destabilizing load force, but not women. Exposure to artificial gravity induced higher heart rate and mean arterial pressure in both sexes compared to baseline. However, during artificial gravity exposure, only women decreased heart rate across sessions. Interestingly, we found that finishers of the protocol (mostly men) and Non-finishers (mostly women) exhibited divergent patterns of hemodynamic responses. Conclusion We speculate that the lack of grip force adaptation reported in women could be linked to the challenged hemodynamic responses during artificial gravity. By deriving a simple model to predict failure to complete the protocol, we found that mean arterial pressure—and not sex of the participant—was the most relevant factor. As artificial gravity is being proposed as a countermeasure in long-term manned missions, the observed effects in grip force adaptation and hemodynamic responses during varying gravito-inertial stressors application are particularly important.
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26
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Goswami N, Blaber AP, Hinghofer-Szalkay H, Convertino VA. Lower Body Negative Pressure: Physiological Effects, Applications, and Implementation. Physiol Rev 2019; 99:807-851. [PMID: 30540225 DOI: 10.1152/physrev.00006.2018] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This review presents lower body negative pressure (LBNP) as a unique tool to investigate the physiology of integrated systemic compensatory responses to altered hemodynamic patterns during conditions of central hypovolemia in humans. An early review published in Physiological Reviews over 40 yr ago (Wolthuis et al. Physiol Rev 54: 566-595, 1974) focused on the use of LBNP as a tool to study effects of central hypovolemia, while more than a decade ago a review appeared that focused on LBNP as a model of hemorrhagic shock (Cooke et al. J Appl Physiol (1985) 96: 1249-1261, 2004). Since then there has been a great deal of new research that has applied LBNP to investigate complex physiological responses to a variety of challenges including orthostasis, hemorrhage, and other important stressors seen in humans such as microgravity encountered during spaceflight. The LBNP stimulus has provided novel insights into the physiology underlying areas such as intolerance to reduced central blood volume, sex differences concerning blood pressure regulation, autonomic dysfunctions, adaptations to exercise training, and effects of space flight. Furthermore, approaching cardiovascular assessment using prediction models for orthostatic capacity in healthy populations, derived from LBNP tolerance protocols, has provided important insights into the mechanisms of orthostatic hypotension and central hypovolemia, especially in some patient populations as well as in healthy subjects. This review also presents a concise discussion of mathematical modeling regarding compensatory responses induced by LBNP. Given the diverse applications of LBNP, it is to be expected that new and innovative applications of LBNP will be developed to explore the complex physiological mechanisms that underline health and disease.
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Affiliation(s)
- Nandu Goswami
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Andrew Philip Blaber
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Helmut Hinghofer-Szalkay
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Victor A Convertino
- Physiology Section, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz , Graz , Austria ; Department of Biomedical Physiology and Kinesiology, Simon Fraser University , Burnaby, British Columbia , Canada ; Battlefield Health & Trauma Center for Human Integrative Physiology, Combat Casualty Care Research Program, US Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
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27
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KROHOVA J, CZIPPELOVA B, TURIANIKOVA Z, LAZAROVA Z, WISZT R, JAVORKA M, FAES L. Information Domain Analysis of Respiratory Sinus Arrhythmia Mechanisms. Physiol Res 2018; 67:S611-S618. [DOI: 10.33549/physiolres.934049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Ventilation related heart rate oscillations – respiratory sinus arrhythmia (RSA) – originate in human from several mechanisms. Two most important of them – the central mechanism (direct communication between respiratory and cardiomotor centers), and the peripheral mechanism (ventilation-associated blood pressure changes transferred to heart rate via baroreflex) have been described in previous studies. The major aim of this study was to compare the importance of these mechanisms in the generation of RSA non-invasively during various states by quantifying the strength of the directed interactions between heart rate, systolic blood pressure and respiratory volume signals. Seventy-eight healthy volunteers (32 male, age range: 16.02-25.77 years, median age: 18.57 years) participated in this study. The strength of mutual interconnections among the spontaneous beat-to-beat oscillations of systolic blood pressure (SBP), R-R interval (RR signal) and respiration (volume changes – RESP signal) was quantified during supine rest, orthostatic challenge (head-up tilt, HUT) and cognitive load (mental arithmetics, MA) using bivariate and trivariate measures of cardio-respiratory information transfer to separate baroreflex and nonbaroreflex (central) mechanisms. Our results indicate that both basic mechanisms take part in RSA generation in the intact cardiorespiratory control of human subjects. During orthostatic and mental challenges baroreflex based peripheral mechanism becomes more important.
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Affiliation(s)
- J. KROHOVA
- Department of Physiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
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28
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Masatli Z, Nordine M, Maggioni MA, Mendt S, Hilmer B, Brauns K, Werner A, Schwarz A, Habazettl H, Gunga HC, Opatz OS. Gender-Specific Cardiovascular Reactions to +Gz Interval Training on a Short Arm Human Centrifuge. Front Physiol 2018; 9:1028. [PMID: 30108517 PMCID: PMC6079353 DOI: 10.3389/fphys.2018.01028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 07/11/2018] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular deconditioning occurs in astronauts during microgravity exposure, and may lead to post-flight orthostatic intolerance, which is more prevalent in women than men. Intermittent artificial gravity is a potential countermeasure, which can effectively train the cardiovascular mechanisms responsible for maintaining orthostatic integrity. Since cardiovascular responses may differ between women and men during gravitational challenges, information regarding gender specific responses during intermittent artificial gravity exposure plays a crucial role in countermeasure strategies. This study implemented a +Gz interval training protocol using a ground based short arm human centrifuge, in order to assess its effectiveness in stimulating the components of orthostatic integrity, such as diastolic blood pressure, heart rate and vascular resistance amongst both genders. Twenty-eight participants (12 men/16 women) underwent a two-round graded +1/2/1 Gz profile, with each +Gz phase lasting 4 min. Cardiovascular parameters from each phase (averaged last 60 sec) were analyzed for significant changes with respect to baseline values. Twelve men and eleven women completed the session without interruption, while five women experienced an orthostatic event. These women had a significantly greater height and baseline mean arterial pressure than their counterparts. Throughout the +Gz interval session, women who completed the session exhibited significant increases in heart rate and systemic vascular resistance index throughout all +Gz phases, while exhibiting increases in diastolic blood pressure during several +Gz phases. Men expressed significant increases from baseline in diastolic blood pressure throughout the session with heart rate increases during the +2Gz phases, while no significant changes in vascular resistance were recorded. Furthermore, women exhibited non-significantly higher heart rates over men during all phases of +Gz. Based on these findings, this protocol proved to consistently stimulate the cardiovascular systems involved in orthostatic integrity to a larger extent amongst women than men. Thus the +Gz gradients used for this interval protocol may be beneficial for women as a countermeasure against microgravity induced cardiovascular deconditioning, whereas men may require higher +Gz gradients. Lastly, this study indicates that gender specific cardiovascular reactions are apparent during graded +Gz exposure while no significant differences regarding cardiovascular responses were found between women and men during intermittent artificial gravity training.
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Affiliation(s)
- Zeynep Masatli
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Nordine
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Martina A Maggioni
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| | - Stefan Mendt
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ben Hilmer
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Katharina Brauns
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anika Werner
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anton Schwarz
- Central Medical School, Monash University, Melbourne, VIC, Australia
| | - Helmut Habazettl
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Hanns-Christian Gunga
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Oliver S Opatz
- Center for Space Medicine and Extreme Environments Berlin, Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Allen K, Chuter KM, Fithon K, Marshall L, Hauton D. Modulation of the orthostatic blood pressure response by acute nitrate consumption is dependent upon ethnic origin. Clin Exp Pharmacol Physiol 2018; 45:1106-1117. [PMID: 30003580 DOI: 10.1111/1440-1681.13010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 11/29/2022]
Abstract
Orthostatic stress triggers a response to maintain cerebral perfusion and prevent syncope. Given the hypotensive effects of inorganic nitrate this response to orthostasis may be altered by acute supplementation with inorganic nitrate and modified by ethnic origin. Caucasian and SE Asian (n = 30 for both), were recruited and subjected to an 'active stand test' and brachial artery blood pressure (BP), digit blood flow and ECG were recorded. Following inorganic nitrate supplementation, (10 mg/kg body mass) the tests were repeated. For both Caucasian and SE Asians transition to standing increased diastolic pressure (DP) and heart rate (HR) (P < 0.001 for both) and by calculation increased rate-pressure product (P < 0.001) and decreased pulse pressure (P < 0.01 for both) indicative of decreased ventricular filling. Nitrate supplementation decreased both DP (P < 0.001) and HR (P < 0.001). Assessment of HR variability suggested sympathetic nerve activity, was higher throughout in Caucasians (P < 0.05) coupled with higher parasympathetic tone (P < 0.01). Nitrate had no effect on cardiac autonomic nerve activity, as estimated using HR variability, for supine or standing subjects. The tachycardia and hypertension associated with orthostatic stress were preserved in both Caucasian and SE Asian subjects, however, we highlight possible differences in autonomic nervous system activity between Caucasians and SE Asians. SE Asians are resistant to the hypotensive effects of inorganic nitrate supplementation suggesting the absence of a crucial mechanism for activation of the nitrate-nitrite-nitric oxide system.
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Affiliation(s)
- Katie Allen
- Faculty of Maths & Physics, School of Food Science & Nutrition, University of Leeds, Leeds, UK
| | - Katie M Chuter
- Faculty of Maths & Physics, School of Food Science & Nutrition, University of Leeds, Leeds, UK
| | - Katherine Fithon
- Faculty of Maths & Physics, School of Food Science & Nutrition, University of Leeds, Leeds, UK
| | - Lisa Marshall
- Faculty of Maths & Physics, School of Food Science & Nutrition, University of Leeds, Leeds, UK
| | - David Hauton
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK.,Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
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30
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Ha SY, Park KM, Park J, Kim SE, Lee BI, Shin KJ. Autonomic function test in progressive lacunar infarction. Acta Neurol Scand 2018; 138:32-40. [PMID: 29468632 DOI: 10.1111/ane.12913] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Neurological progression is a major problem in managing the patients with acute lacunar infarction. The purpose of this was to investigate whether autonomic dysfunction is associated with neurological progression in patients with acute lacunar infarction. MATERIALS AND METHODS The study comprised 60 patients with acute lacunar infarction. All enrolled subjects underwent autonomic function tests including the 30° head-up tilt test, Valsalva test, heart rate response to deep breathing, and sympathetic skin response. The primary endpoint is the neurological progression, and the secondary endpoint is the 3-month outcome. RESULTS Increased initial National Institute of Health stroke scale (NIHSS), decreased time to admission from onset, decreased rise of heart rate in the 30° head-up tilt test, abnormal blood pressure response in the Valsalva test, and decreased rise of systolic blood pressure in stage IV of the Valsalva test are associated with neurological progression of acute lacunar infarction; an abnormal blood pressure response in the Valsalva test is significant in logistic regression analysis of neurological progression. Advanced age, increased initial NIHSS and modified Rankin scale, decreased expiration/inspiration ratio of heart rate to deep breathing, decreased rise of systolic blood pressure in stage IV of the Valsalva test, and neurological progression were associated with an unfavorable 3-month outcome; neurological progression was significant in logistic regression analysis of 3-month outcome. CONCLUSIONS An abnormal blood pressure change in the Valsalva test is associated with neurological progression in patients with acute lacunar infarction, and neurological progression can induce an unfavorable 3-month outcome.
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Affiliation(s)
- S. Y. Ha
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
| | - K. M. Park
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
| | - J. Park
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
| | - S. E. Kim
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
| | - B. I. Lee
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
| | - K. J. Shin
- Department of Neurology; Haeundae-Paik Hospital; College of Medicine; Inje University; Busan Korea
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31
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Javorka M, El-Hamad F, Czippelova B, Turianikova Z, Krohova J, Lazarova Z, Baumert M. Role of respiration in the cardiovascular response to orthostatic and mental stress. Am J Physiol Regul Integr Comp Physiol 2018; 314:R761-R769. [PMID: 29443551 DOI: 10.1152/ajpregu.00430.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to determine the response of heart rate and blood pressure variability (respiratory sinus arrhythmia, baroreflex sensitivity) to orthostatic and mental stress, focusing on causality and the mediating effect of respiration. Seventy-seven healthy young volunteers (46 women, 31 men) aged 18.4 ± 2.7 yr underwent an experimental protocol comprising supine rest, 45° head-up tilt, recovery, and a mental arithmetic task. Heart rate variability and blood pressure variability were analyzed in the time and frequency domain and modeled as a multivariate autoregressive process where the respiratory volume signal acted as an external driver. During head-up tilt, tidal volume increased while respiratory rate decreased. During mental stress, breathing rate increased and tidal volume was elevated slightly. Respiratory sinus arrhythmia decreased during both interventions. Baroreflex function was preserved during orthostasis but was decreased during mental stress. While sex differences were not observed during baseline conditions, cardiovascular response to orthostatic stress and respiratory response to mental stress was more prominent in men compared with women. The respiratory response to the mental arithmetic tasks was more prominent in men despite a significantly higher subjectively perceived stress level in women. In conclusion, respiration shows a distinct response to orthostatic versus mental stress, mediating cardiovascular variability; it needs to be considered for correct interpretation of heart rate and blood pressure phenomena.
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Affiliation(s)
- Michal Javorka
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Fatima El-Hamad
- School of Electrical and Electronic Engineering, The University of Adelaide, South Australia, Australia
| | - Barbora Czippelova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Zuzana Turianikova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Jana Krohova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Zuzana Lazarova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia.,Department of Physiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - Mathias Baumert
- School of Electrical and Electronic Engineering, The University of Adelaide, South Australia, Australia
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Goswami N, Blaber AP, Hinghofer-Szalkay H, Montani JP. Orthostatic Intolerance in Older Persons: Etiology and Countermeasures. Front Physiol 2017; 8:803. [PMID: 29163185 PMCID: PMC5677785 DOI: 10.3389/fphys.2017.00803] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/29/2017] [Indexed: 12/16/2022] Open
Abstract
Orthostatic challenge produced by upright posture may lead to syncope if the cardiovascular system is unable to maintain adequate brain perfusion. This review outlines orthostatic intolerance related to the aging process, long-term bedrest confinement, drugs, and disease. Aging-associated illness or injury due to falls often leads to hospitalization. Older patients spend up to 83% of hospital admission lying in bed and thus the consequences of bedrest confinement such as physiological deconditioning, functional decline, and orthostatic intolerance represent a central challenge in the care of the vulnerable older population. This review examines current scientific knowledge regarding orthostatic intolerance and how it comes about and provides a framework for understanding of (patho-) physiological concepts of cardiovascular (in-) stability in ambulatory and bedrest confined senior citizens as well as in individuals with disease conditions [e.g., orthostatic intolerance in patients with diabetes mellitus, multiple sclerosis, Parkinson's, spinal cord injury (SCI)] or those on multiple medications (polypharmacy). Understanding these aspects, along with cardio-postural interactions, is particularly important as blood pressure destabilization leading to orthostatic intolerance affects 3-4% of the general population, and in 4 out of 10 cases the exact cause remains elusive. Reviewed also are countermeasures to orthostatic intolerance such as exercise, water drinking, mental arithmetic, cognitive training, and respiration training in SCI patients. We speculate that optimally applied countermeasures such as mental challenge maintain sympathetic activity, and improve venous return, stroke volume, and consequently, blood pressure during upright standing. Finally, this paper emphasizes the importance of an active life style in old age and why early re-mobilization following bedrest confinement or bedrest is crucial in preventing orthostatic intolerance, falls and falls-related injuries in older persons.
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Affiliation(s)
- Nandu Goswami
- Gravitational Physiology and Medicine Research Unit, Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Andrew P Blaber
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Helmut Hinghofer-Szalkay
- Gravitational Physiology and Medicine Research Unit, Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Jean-Pierre Montani
- Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland
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Sarafian D, Miles-Chan JL. The Influence of Gender and Anthropometry on Haemodynamic Status at Rest and in Response to Graded Incremental Head-Up Tilt in Young, Healthy Adults. Front Physiol 2017; 7:656. [PMID: 28101061 PMCID: PMC5209346 DOI: 10.3389/fphys.2016.00656] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/14/2016] [Indexed: 01/02/2023] Open
Abstract
The body's ability to rapidly and appropriately regulate blood pressure in response to changing physiological demand is a key feature of a healthy cardiovascular system. Passively tilting the body, thereby changing central blood volume, is a well-recognized and controlled method of evaluating this ability. However, such studies usually involve single tilt angles, or intermittent tilting separated by supine, resting periods; valuable information concerning the adaptive capacity of the regulatory systems involved is therefore currently lacking. Furthermore, despite increasing recognition that men and women differ in the magnitude of their haemodynamic response to such stimuli, little is known about the degree to which gender differences in body composition and anthropometry influence these regulatory pathways, or indeed if these differences are apparent in response to graded, incremental tilting. In the present study we measured, in 23 young, healthy adults (13 men, 10 women), the continuous beat-to-beat haemodynamic response to graded, incremental tilting (0°, 20°, 40°, 60°, and back to 40°) with each tilt angle lasting 16 min. On average, we observed increases in heart rate (+41%), blood pressure (+10%), and total peripheral resistance (+16%) in response to tilting. However, whilst men showed an immediate decrease in cardiac output upon tilting (−8.9%) cardiac output in women did not change significantly from supine values. Interestingly, the decrease in stroke volume observed in women was significantly less than that observed in men (−22 vs. −36%, p < 0.05); although the present study could not determine if this difference was due to gender per se or due to differences in body size (in particular height) between the two gender groups. Such disparities in the magnitude of autonomic response may indicate (in the case of our gradual incremental tilt procedure) a better buffering capacity to progressive changes in central blood volume in women; which warrants further investigation, particularly in light of the well-recognized differences in cardiovascular disease risk between men and women.
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Affiliation(s)
- Delphine Sarafian
- Laboratory of Integrative Cardiovascular and Metabolic Physiology, Division of Physiology, Department of Medicine, University of Fribourg Fribourg, Switzerland
| | - Jennifer L Miles-Chan
- Laboratory of Integrative Cardiovascular and Metabolic Physiology, Division of Physiology, Department of Medicine, University of Fribourg Fribourg, Switzerland
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