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Respiratory and heart rate dynamics during peripheral chemoreceptor deactivation compared to targeted sympathetic and sympathetic/parasympathetic (co-)activation. Auton Neurosci 2022; 241:103009. [PMID: 35753247 DOI: 10.1016/j.autneu.2022.103009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/29/2022] [Accepted: 06/13/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND The importance of peripheral chemoreceptors for cardiorespiratory neural control is known for decades. Pure oxygen inhalation deactivates chemoreceptors and increases parasympathetic outflow. However, the relationship between autonomic nervous system (ANS) activation and resulting respiratory as well as heart rate (HR) dynamics is still not fully understood. METHODS In young adults the impact of (1) 100 % pure oxygen inhalation (hyperoxic cardiac chemoreflex sensitivity (CHRS) testing), (2) the cold face test (CFT) and (3) the cold pressor test (CPT) on heart rate variability (HRV), hemodynamics and respiratory rate was investigated in randomized order. Baseline ANS outflow was determined assessing respiratory sinus arrhythmia via deep breathing, baroreflex sensitivity and HRV. RESULTS Baseline ANS outflow was normal in all participants (23 ± 1 years, 7 females, 3 males). Hyperoxic CHRS testing decreased HR (after 60 ± 3 vs before 63 ± 3 min-1, p = 0.004), while increasing total peripheral resistance (1053 ± 87 vs 988 ± 76 dyne*s + m2/cm5, p = 0.02) and mean arterial blood pressure (93 ± 4 vs 91 ± 4 mm Hg, p = 0.02). HRV indicated increased parasympathetic outflow after hyperoxic CHRS testing accompanied by a decrease in respiratory rate (15 ± 1vs 19 ± 1 min-1, p = 0.001). In contrast, neither CFT nor CPT altered the respiratory rate (18 ± 1 vs 18 ± 2 min-1, p = 0.38 and 18 ± 1 vs 18 ± 1 min-1, p = 0.84, respectively). CONCLUSION Changes in HR characteristics during deactivation of peripheral chemoreceptors but not during the CFT and CPT are related with a decrease in respiratory rate. This highlights the need of respiratory rate assessment when evaluating adaptations of cardiorespiratory chemoreceptor control.
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Boutou AK, Dipla K, Theodorakopoulou MP, Markopoulou K, Pitsiou G, Papadopoulos S, Kritikou S, Stanopoulos I, Zafeiridis A. Effects of oxygen supplementation in autonomic nervous system function during exercise in patients with idiopathic pulmonary fibrosis and exertional desaturation. CLINICAL RESPIRATORY JOURNAL 2021; 15:1088-1096. [PMID: 34143559 DOI: 10.1111/crj.13412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/05/2021] [Accepted: 06/08/2021] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Patients with idiopathic pulmonary fibrosis (IPF) have reduced exercise capacity and often present exertional dyspnea and desaturation. The role of autonomic nervous system (ANS) as a pathogenetic contributor to this dysfunction has not been evaluated. OBJECTIVE To evaluate whether improvement of arterial oxygen saturation (SpO2 ) via oxygen supplementation results to ANS function improvement, during steady state submaximal exercise. METHODS This is a secondary analysis of a single-blind, randomized, placebo-controlled, cross-over trial, including 12 IPF patients, with isolated exertional desaturation. Following a maximal cardiopulmonary test, participants underwent two submaximal steady state tests during which they received either supplementary oxygen or medical air. Continuous beat-to-beat blood pressure measurements were recorded (Finapres Medical Systems, Amsterdam, The Netherlands). Autonomic function was assessed non-invasively by heart rate variability (HRV); root mean square of successive differences (RMSSD) and standard-deviation-Poincare-plot (SD1) were used as indices of parasympathetic output. Entropy and detrended fluctuation analysis (DFA) were also used. RESULTS During rest, oxygen supplementation did not significantly alter RMSSD and SD1. During exercise, subjects presented no significant alterations compared with baseline, in most HRV indices examined. There was no improvement of this behavior with O2 -supplementation. Approximate-entropy increased during exercise, with no differences between protocols. CONCLUSIONS IPF patients presented an inadequate adaptive response of their ANS to exercise and recovery. Although oxygen supplementation significantly prolonged exercise duration and prevented the substantial exertional desaturation, the blunted vagal response to steady-state exercise in these patients was not improved, suggesting that acute oxygen supplementation does not sufficiently improve ANS dysfunction in these patients.
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Affiliation(s)
- Afroditi K Boutou
- Department of Respiratory Medicine, G. Papanikolaou Hospital, Thessaloniki, Greece
| | - Konstantina Dipla
- Exercise Physiology & Biochemistry Laboratory, Department of Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Katerina Markopoulou
- Department of Respiratory Medicine, G. Papanikolaou Hospital, Thessaloniki, Greece
| | - Georgia Pitsiou
- Department of Respiratory Failure, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stavros Papadopoulos
- Exercise Physiology & Biochemistry Laboratory, Department of Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stella Kritikou
- Exercise Physiology & Biochemistry Laboratory, Department of Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Ioannis Stanopoulos
- Department of Respiratory Failure, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Andreas Zafeiridis
- Exercise Physiology & Biochemistry Laboratory, Department of Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Yu YL, Thijs L, Yu CG, Yang WY, Melgarejo JD, Wei DM, Wei FF, Nawrot TS, Verhamme P, Roels HA, Staessen JA, Zhang ZY. Two-Year Responses of Heart Rate and Heart Rate Variability to First Occupational Lead Exposure. Hypertension 2021; 77:1775-1786. [PMID: 33775124 DOI: 10.1161/hypertensionaha.120.16545] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Yu-Ling Yu
- From the Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (Y.-L.Y., L.T., J.D.M., D.-M.W., Z.-Y.Z.).,Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China (Y.-L.Y.)
| | - Lutgarde Thijs
- From the Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (Y.-L.Y., L.T., J.D.M., D.-M.W., Z.-Y.Z.)
| | - Cai-Guo Yu
- Center for Endocrine Metabolism and Immune Diseases, Beijing Luhe Hospital and Key Laboratory of Diabetes Prevention and Research, Capital Medical University, China (C.-G.Y.)
| | - Wen-Yi Yang
- Department of Cardiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, China (W.-Y.Y.)
| | - Jesus D Melgarejo
- From the Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (Y.-L.Y., L.T., J.D.M., D.-M.W., Z.-Y.Z.)
| | - Dong-Mei Wei
- From the Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (Y.-L.Y., L.T., J.D.M., D.-M.W., Z.-Y.Z.)
| | - Fang-Fei Wei
- Department of Cardiology, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China (F.-F.W.)
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium (T.S.N., H.A.R.)
| | - Peter Verhamme
- Centre for Molecular and Vascular Biology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (P.V.)
| | - Harry A Roels
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium (T.S.N., H.A.R.)
| | - Jan A Staessen
- Research Institute Alliance for the Promotion of Preventive Medicine (J.A.S.).,Biomedical Science Group, Faculty of Medicine, University of Leuven, Belgium (J.A.S.)
| | - Zhen-Yu Zhang
- From the Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Belgium (Y.-L.Y., L.T., J.D.M., D.-M.W., Z.-Y.Z.)
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Siński M, Lewandowski J, Dobosiewicz A, Przybylski J, Abramczyk P, Gaciong Z. The effect of hyperoxia on central blood pressure in healthy subjects. Arch Med Sci 2016; 12:992-999. [PMID: 27695489 PMCID: PMC5016570 DOI: 10.5114/aoms.2015.49038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/30/2015] [Indexed: 01/04/2023] Open
Abstract
INTRODUCTION Hyperoxia increases total peripheral resistance by acting locally but also inhibits the activity of carotid body chemoreceptors. We studied the effect of hyperoxia on central pressure in normotensive subjects. MATERIAL AND METHODS Medical air followed by 100% oxygen was provided to 19 subjects (12/7 female/male, age 28.2 ±1.1 years) for 15 min through a non-rebreather mask. Central blood pressure was then measured using applanation tonometry. RESULTS After the first 2 min of hyperoxia, heart rate decreased significantly (65 ±2.6 beats/min vs. 61 ±2.1 beats/min, p = 0.0002). Peripheral and central blood pressure remained unchanged, while hemoglobin oxygen saturation and subendocardial viability ratio index increased (97 ±0.4% vs. 99 ±0.2%, p = 0.03; 168 ±8.4% vs. 180 ±8.2%, p = 0.009). After 15 min of 100% oxygen ventilation, heart rate and peripheral and central blood pressures remained unchanged from the first 2 min. The augmentation index, augmentation pressure and ejection duration increased as compared to baseline values and those obtained at 2 min (-5.1 ±2.9% vs. -1.2 ±2.6%, p = 0.005 and -4.6 ±2.7% vs. -1.2 ±2.6%, p = 0.0015; -1.3 ±0.7 mm Hg vs. -0.2 ±1.2 mm Hg, p = 0.003 and -1.1 ±0.7 mm Hg vs. -0.2 ±1.2 mm Hg, p = 0.012; 323 ±3.6 ms vs. 330 ±3.5 ms, p = 0.0002 and 326 ±3.5 ms vs. 330 ±3.5 ms, p = 0.021, respectively). CONCLUSIONS The present study shows that hyperoxia does not affect central blood pressure in young healthy subjects and may improve myocardial blood supply estimated indirectly from applanation tonometry.
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Affiliation(s)
- Maciej Siński
- Department of Internal Medicine, Hypertension and Vascular Diseases, Medical University of Warsaw, Warsaw, Poland
| | - Jacek Lewandowski
- Department of Internal Medicine, Hypertension and Vascular Diseases, Medical University of Warsaw, Warsaw, Poland
| | - Anna Dobosiewicz
- Department of Pulmonary Circulation and Thromboembolic Diseases, Center of Postgraduate Medical Education, Otwock, Poland
| | - Jacek Przybylski
- Department of Biophysics and Physiology, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Abramczyk
- Department of Internal Medicine, Hypertension and Vascular Diseases, Medical University of Warsaw, Warsaw, Poland
| | - Zbigniew Gaciong
- Department of Internal Medicine, Hypertension and Vascular Diseases, Medical University of Warsaw, Warsaw, Poland
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5
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Milstein DMJ, Helmers R, Hackmann S, Belterman CNW, van Hulst RA, de Lange J. Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia. Microvasc Res 2016; 105:93-102. [PMID: 26851620 DOI: 10.1016/j.mvr.2016.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 10/22/2022]
Abstract
Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0 bar) and HB (2.5 bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states.
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Affiliation(s)
- Dan M J Milstein
- Department of Oral & Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
| | - Renée Helmers
- Department of Oral & Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands
| | - Sanne Hackmann
- Department of Large Laboratory Animals, Animal Research Institute Academic Medical Center (ARIA), University of Amsterdam, Meibergdreef 31, 1105 AZ, The Netherlands
| | - Charly N W Belterman
- Department of Experimental Cardiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands
| | - Robert A van Hulst
- Department of Hyperbaric Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; Diving Medical Center, Royal Netherlands Navy, PO Box 10000, 1780 CA Den Helder, The Netherlands; Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands
| | - Jan de Lange
- Department of Oral & Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands
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Helmerhorst HJF, Roos-Blom MJ, van Westerloo DJ, Abu-Hanna A, de Keizer NF, de Jonge E. Associations of arterial carbon dioxide and arterial oxygen concentrations with hospital mortality after resuscitation from cardiac arrest. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:348. [PMID: 26415731 PMCID: PMC4587673 DOI: 10.1186/s13054-015-1067-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 09/12/2015] [Indexed: 01/21/2023]
Abstract
Introduction Arterial concentrations of carbon dioxide (PaCO2) and oxygen (PaO2) during admission to the intensive care unit (ICU) may substantially affect organ perfusion and outcome after cardiac arrest. Our aim was to investigate the independent and synergistic effects of both parameters on hospital mortality. Methods This was a cohort study using data from mechanically ventilated cardiac arrest patients in the Dutch National Intensive Care Evaluation (NICE) registry between 2007 and 2012. PaCO2 and PaO2 levels from arterial blood gas analyses corresponding to the worst oxygenation in the first 24 h of ICU stay were retrieved for analyses. Logistic regression analyses were performed to assess the relationship between hospital mortality and both categorized groups and a spline-based transformation of the continuous values of PaCO2 and PaO2. Results In total, 5,258 cardiac arrest patients admitted to 82 ICUs in the Netherlands were included. In the first 24 h of ICU admission, hypocapnia was encountered in 22 %, and hypercapnia in 35 % of included cases. Hypoxia and hyperoxia were observed in 8 % and 3 % of the patients, respectively. Both PaCO2 and PaO2 had an independent U-shaped relationship with hospital mortality and after adjustment for confounders, hypocapnia and hypoxia were significant predictors of hospital mortality: OR 1.37 (95 % CI 1.17–1.61) and OR 1.34 (95 % CI 1.08–1.66). A synergistic effect of concurrent derangements of PaCO2 and PaO2 was not observed (P = 0.75). Conclusions The effects of aberrant arterial carbon dioxide and arterial oxygen concentrations were independently but not synergistically associated with hospital mortality after cardiac arrest. Electronic supplementary material The online version of this article (doi:10.1186/s13054-015-1067-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hendrik J F Helmerhorst
- Department of Intensive Care Medicine, Leiden University Medical Center, Post Box 9600, Leiden, 2300 RC, The Netherlands. .,Laboratory of Experimental Intensive Care and Anesthesiology, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
| | - Marie-José Roos-Blom
- Department of Medical Informatics, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. .,National Intensive Care Evaluation (NICE) foundation, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
| | - David J van Westerloo
- Department of Intensive Care Medicine, Leiden University Medical Center, Post Box 9600, Leiden, 2300 RC, The Netherlands.
| | - Ameen Abu-Hanna
- Department of Medical Informatics, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
| | - Nicolette F de Keizer
- Department of Medical Informatics, Academic Medical Center, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. .,National Intensive Care Evaluation (NICE) foundation, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
| | - Evert de Jonge
- Department of Intensive Care Medicine, Leiden University Medical Center, Post Box 9600, Leiden, 2300 RC, The Netherlands. .,National Intensive Care Evaluation (NICE) foundation, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
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7
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Computation of nonlinear parameters of heart rhythm using short time ECG segments. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2015; 2015:983479. [PMID: 25688286 PMCID: PMC4320930 DOI: 10.1155/2015/983479] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/15/2014] [Accepted: 09/30/2014] [Indexed: 11/17/2022]
Abstract
We propose the method to compute the nonlinear parameters of heart rhythm (correlation dimension D₂ and correlation entropy K₂) using 5-minute ECG recordings preferred for screening of population. Conversion of RR intervals' time series into continuous function x(t) allows getting the new time series with different sampling rate dt. It has been shown that for all dt (250, 200, 125, and 100 ms) the cross-plots of D₂ and K₂ against embedding dimension m for phase-space reconstruction start to level off at m = 9. The sample size N at different sampling rates varied from 1200 at dt = 250 ms to 3000 at dt = 100 ms. Along with, the D₂ and K₂ means were not statistically different; that is, the sampling rate did not influence the results. We tested the feasibility of the method in two models: nonlinear heart rhythm dynamics in different states of autonomous nervous system and age-related characteristics of nonlinear parameters. According to the acquired data, the heart rhythm is more complex in childhood and adolescence with more influential parasympathetic influence against the background of elevated activity of sympathetic autonomous nervous system.
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8
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Amiya E, Watanabe M, Komuro I. The Relationship between Vascular Function and the Autonomic Nervous System. Ann Vasc Dis 2014; 7:109-19. [PMID: 24995054 PMCID: PMC4072858 DOI: 10.3400/avd.ra.14-00048] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/22/2014] [Indexed: 12/23/2022] Open
Abstract
Endothelial dysfunction and autonomic nervous system dysfunction are both risk factors for atherosclerosis. There is evidence demonstrating that there is a close interrelationship between these two systems. In hypertension, endothelial dysfunction affects the pathologic process through autonomic nervous pathways, and the pathophysiological process of autonomic neuropathy in diabetes mellitus is closely related with vascular function. However, detailed mechanisms of this interrelationship have not been clearly explained. In this review, we summarize findings concerning the interrelationship between vascular function and the autonomic nervous system from both experimental and clinical studies. The clarification of this interrelationship may provide more comprehensive risk stratification and a new effective therapeutic strategy against atherosclerosis.
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Affiliation(s)
- Eisuke Amiya
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masafumi Watanabe
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Vaijeyanthi V, Vishnuprasad K, Kumar CS, Ramachandran KI, Gopinath R, Kumar AA, Yadav PK. Towards enhancing the performance of multi-parameter patient monitors. Healthc Technol Lett 2014; 1:19-20. [PMID: 26609370 DOI: 10.1049/htl.2013.0041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/12/2014] [Accepted: 02/18/2014] [Indexed: 11/19/2022] Open
Abstract
Multi-parameter patient monitors (MPMs) have become increasingly important in providing quality healthcare to patients. It is well known in the medical community that there exists an intrinsic relationship between different vital parameters in a healthy person, these include heart rate, blood pressure, respiration rate and oxygen saturation. For example, an increase in blood pressure would lead to a decrease in the heart rate, and vice versa. Although it is likely to improve the performance of MPM systems, this fact is not explored in engineering research. In this work, experiments show that deriving additional features to capture the intrinsic relationship between the vital parameters, the alarm accuracy (sensitivity), no-alarm accuracy (specificity) and the overall performance of MPMs can be improved. The geometric mean of the product of all the vital parameters taken in pairs of two was used to capture the intrinsic relationship between the different parameters. An improvement of 10.55% for sensitivity, 0.32% for specificity and an overall performance improvement of 1.03% was obtained, compared to the baseline system using classification and regression tree with the four vital parameters.
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Affiliation(s)
- V Vaijeyanthi
- Department of Electronics and Communication Engineering , Machine Intelligence Research Laboratory , Amrita Vishwa Vidyapeetham , Amritanagar , Coimbatore , India
| | - K Vishnuprasad
- Department of Electronics and Communication Engineering , Machine Intelligence Research Laboratory , Amrita Vishwa Vidyapeetham , Amritanagar , Coimbatore , India
| | - C Santhosh Kumar
- Department of Electronics and Communication Engineering , Machine Intelligence Research Laboratory , Amrita Vishwa Vidyapeetham , Amritanagar , Coimbatore , India
| | - K I Ramachandran
- Department of Electronics and Communication Engineering , Machine Intelligence Research Laboratory , Amrita Vishwa Vidyapeetham , Amritanagar , Coimbatore , India
| | - R Gopinath
- Department of Electronics and Communication Engineering , Machine Intelligence Research Laboratory , Amrita Vishwa Vidyapeetham , Amritanagar , Coimbatore , India
| | - A Anand Kumar
- Department of Neurology , Amrita Institute of Medical Sciences , Cochin , India
| | - Praveen Kumar Yadav
- Department of Neurology , Amrita Institute of Medical Sciences , Cochin , India
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Limberg JK, Taylor JL, Dube S, Basu R, Basu A, Joyner MJ, Wehrwein EA. Role of the carotid body chemoreceptors in baroreflex control of blood pressure during hypoglycaemia in humans. Exp Physiol 2014; 99:640-50. [PMID: 24414173 DOI: 10.1113/expphysiol.2013.076869] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Activation of the carotid body chemoreceptors with hypoxia alters baroreceptor-mediated responses. We aimed to examine whether this relationship can be translated to other chemoreceptor stimuli (i.e. hypoglycaemia) by testing the following hypotheses: (i) activation of the carotid body chemoreceptors with hypoglycaemia would reduce spontaneous cardiac baroreflex sensitivity (sCBRS) in healthy humans; and (ii) desensitization of the carotid chemoreceptors with hyperoxia would restore sCBRS to baseline levels during hypoglycaemia. Ten young healthy adults completed two 180 min hyperinsulinaemic [2 mU (kg fat-free mass)(-1) min(-1)], hypoglycaemic (∼ 3.2 μmol ml(-1)) clamps, separated by at least 1 week and randomized to normoxia (arterial partial pressure of O2, 122 ± 10 mmHg) or hyperoxia (arterial partial pressure of O2, 424 ± 123 mmHg; to blunt activation of the carotid body glomus cells). Changes in heart rate, blood pressure, plasma catecholamines, heart rate variability (HRV) and sCBRS were assessed. During hypoglycaemia, HRV and sCBRS were reduced (P < 0.05) and the baroreflex working range was shifted to higher heart rates. When hyperoxia was superimposed on hypoglycaemia, there was a greater reduction in blood pressure and a blunted rise in heart rate when compared with normoxic conditions (P < 0.05); however, there was no detectable effect of hyperoxia on sCBRS or HRV during hypoglycaemia (P > 0.05). In summary, hypoglycaemia-mediated changes in HRV and sCBRS cannot be attributed exclusively to the carotid chemoreceptors; however, the chemoreceptors appear to play a role in resetting the baroreflex working range during hypoglycaemia.
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Affiliation(s)
- Jacqueline K Limberg
- * Department of Anesthesiology, Mayo Clinic, 200 1st Street SW, SMH Joseph 4-184, Rochester, MN 55905, USA.
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Porta A, Żebrowski J. Inferring cardiovascular control from spontaneous variability. Auton Neurosci 2013; 178:1-3. [PMID: 23746470 DOI: 10.1016/j.autneu.2013.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Indexed: 11/25/2022]
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