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The role of the autonomic nervous system in arrhythmias and sudden cardiac death. Auton Neurosci 2017; 205:1-11. [PMID: 28392310 DOI: 10.1016/j.autneu.2017.03.005] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 03/11/2017] [Accepted: 03/28/2017] [Indexed: 12/16/2022]
Abstract
The autonomic nervous system (ANS) is complex and plays an important role in cardiac arrhythmia pathogenesis. A deeper understanding of the anatomy and development of the ANS has shed light on its involvement in cardiac arrhythmias. Alterations in levels of Sema-3a and NGF, both growth factors involved in innervation patterning during development of the ANS, leads to cardiac arrhythmias. Dysregulation of the ANS, including polymorphisms in genes involved in ANS development, have been implicated in sudden infant death syndrome. Disruptions in the sympathetic and/or parasympathetic systems of the ANS can lead to cardiac arrhythmias and can vary depending on the type of arrhythmia. Simultaneous stimulation of both the sympathetic and parasympathetic systems is thought to lead to atrial fibrillation whereas increased sympathetic stimulation is thought to lead to ventricular fibrillation or ventricular tachycardia. In inherited arrhythmia syndromes, such as Long QT and Catecholaminergic Polymorphic Ventricular Tachycardia, sympathetic system stimulation is thought to lead to ventricular tachycardia, subsequent arrhythmias, and in severe cases, cardiac death. On the other hand, arrhythmic events in Brugada Syndrome have been associated with periods of high parasympathetic tone. Increasing evidence suggests that modulation of the ANS as a therapeutic strategy in the treatment of cardiac arrhythmias is safe and effective. Further studies investigating the involvement of the ANS in arrhythmia pathogenesis and its modulation for the treatment of cardiac arrhythmias is warranted.
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Natali JES, Starzynski PN, Chaui-Berlinck JG. Oscillatory patterns in heart rate variability and complexity: A meta-analysis. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2016.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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53
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Abstract
Numerous animal cardiac exercise models using animal subjects have been established to uncover the cardiovascular physiological mechanism of exercise or to determine the effects of exercise on cardiovascular health and disease. In most cases, animal-based cardiovascular exercise modalities include treadmill running, swimming, and voluntary wheel running with a series of intensities, times, and durations. Those used animals include small rodents (e.g., mice and rats) and large animals (e.g., rabbits, dogs, goats, sheep, pigs, and horses). Depending on the research goal, each experimental protocol should also describe whether its respective exercise treatment can produce the anticipated acute or chronic cardiovascular adaptive response. In this chapter, we will briefly describe the most common kinds of animal models of acute and chronic cardiovascular exercises that are currently being conducted and are likely to be chosen in the near future. Strengths and weakness of animal-based cardiac exercise modalities are also discussed.
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Botek M, Krejčí J, McKune AJ, Klimešová I. Somatic, Endurance Performance and Heart Rate Variability Profiles of Professional Soccer Players Grouped According to Age. J Hum Kinet 2016; 54:65-74. [PMID: 28031758 PMCID: PMC5187960 DOI: 10.1515/hukin-2016-0035] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
This cross-sectional study compared somatic, endurance performance determinants and heart rate variability (HRV) profiles of professional soccer players divided into different age groups: GI (17–19.9 years; n = 23), GII (20–24.9 years; n = 45), GIII (25–29.9 years; n = 30), and GIV (30–39 years; n = 26). Players underwent somatic and HRV assessment and maximal exercise testing. HRV was analyzed by spectral analysis of HRV, and high (HF) and low (LF) frequency power was transformed by a natural logarithm (Ln). Players in GIV (83 ± 7 kg) were heavier (p < 0.05) compared to both GI (73 ± 6 kg), and GII (78 ± 6 kg). Significantly lower maximal oxygen uptake (VO2max, ml•kg-1•min-1) was observed for GIV (56.6 ± 3.8) compared to GI (59.6 ± 3.9), GII (59.4 ± 4.2) and GIV (59.7 ± 4.1). All agegroups, except for GII, demonstrated comparable relative maximal power output (Pmax). For supine HRV, significantly lower Ln HF (ms2) was identified in both GIII (7.1 ± 0.8) and GIV (6.9 ± 1.0) compared to GI (7.9 ± 0.6) and GII (7.7 ± 0.9). In conclusion, soccer players aged >25 years showed negligible differences in Pmax unlike the age group differences demonstrated in VO2max. A shift towards relative sympathetic dominance, particularly due to reduced vagal activity, was apparent after approximately 8 years of competing at the professional level.
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Affiliation(s)
- Michal Botek
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czech Republic
| | - Jakub Krejčí
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czech Republic
| | - Andrew J McKune
- Discipline of Sport and Exercise Science, Faculty of Health, UC-Research Institute for Sport and Exercise, University of Canberra, ACT, Australia; Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Iva Klimešová
- Department of Natural Sciences in Kinanthropology, Faculty of Physical Culture, Palacký University Olomouc, Olomouc, Czech Republic
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Xie L, Liu B, Wang X, Mei M, Li M, Yu X, Zhang J. Effects of different stresses on cardiac autonomic control and cardiovascular coupling. J Appl Physiol (1985) 2016; 122:435-445. [PMID: 27979981 DOI: 10.1152/japplphysiol.00245.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 10/24/2016] [Accepted: 12/07/2016] [Indexed: 12/21/2022] Open
Abstract
The objective of this study was to investigate the impacts of different stresses on time-varying autonomic reactivity and cardiovascular coupling. In total, 25 male subjects were recruited. RR intervals (RRI), systolic and diastolic blood pressure (SBP, DBP), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR) values were collected during rest, mental arithmetic task (MAT), and cold pressor test (CPT). Baroreflex sensitivity (BRS) was derived using the transfer function method. Continuous wavelet transformation of RRI was used to describe the time-variant patterns of autonomic neural activities. Wavelet cross correlation and phase synchronization were used to estimate the amplitude and phase coupling between RRI and SBP. MAT was characterized by increased heart rate (HR), SBP, DBP, and CO with decreased BRS attributable to prolonged parasympathetic withdrawal. Moreover, cardiovascular coupling was disrupted in MAT. These results indicated that baroreflex was depressed, and the top-down system started to take action under mental stress. In CPT, SBP, DBP, and SVR increased significantly, whereas HR and BRS remained unchanged. The increase of sympathetic activity was transient, and cardiovascular coupling did not change in CPT. Intriguingly, the frequency of the maximum cross-correlation coefficient in the low-frequency band (0.04-0.15 Hz) was significantly decreased in CPT, which may be due to the change of resonance frequency of the baroreflex loop.NEW & NOTEWORTHY The study is the first to compare the time-variant pattern of autonomic nervous activities and cardiovascular coupling between the mental arithmetic task (MAT) and the cold pressor test (CPT). Our results demonstrated that MAT and CPT elicited different time-varying patterns of autonomic neural activities and cardiovascular synchronization. Both the amplitude and phase consistency of blood pressure and heart rate decreased in MAT. CPT may affect the harmonic frequency of the baroreflex loop.
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Affiliation(s)
- Lin Xie
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
| | - Binbin Liu
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
| | - Xiaoni Wang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
| | - Mengqi Mei
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
| | - Mengjun Li
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
| | - Xiaolin Yu
- Department of Information Engineering, Officers College of CAPF, Chengdu, China
| | - Jianbao Zhang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China; and
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Végh AMD, Duim SN, Smits AM, Poelmann RE, Ten Harkel ADJ, DeRuiter MC, Goumans MJ, Jongbloed MRM. Part and Parcel of the Cardiac Autonomic Nerve System: Unravelling Its Cellular Building Blocks during Development. J Cardiovasc Dev Dis 2016; 3:jcdd3030028. [PMID: 29367572 PMCID: PMC5715672 DOI: 10.3390/jcdd3030028] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 02/06/2023] Open
Abstract
The autonomic nervous system (cANS) is essential for proper heart function, and complications such as heart failure, arrhythmias and even sudden cardiac death are associated with an altered cANS function. A changed innervation state may underlie (part of) the atrial and ventricular arrhythmias observed after myocardial infarction. In other cardiac diseases, such as congenital heart disease, autonomic dysfunction may be related to disease outcome. This is also the case after heart transplantation, when the heart is denervated. Interest in the origin of the autonomic nerve system has renewed since the role of autonomic function in disease progression was recognized, and some plasticity in autonomic regeneration is evident. As with many pathological processes, autonomic dysfunction based on pathological innervation may be a partial recapitulation of the early development of innervation. As such, insight into the development of cardiac innervation and an understanding of the cellular background contributing to cardiac innervation during different phases of development is required. This review describes the development of the cANS and focuses on the cellular contributions, either directly by delivering cells or indirectly by secretion of necessary factors or cell-derivatives.
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Affiliation(s)
- Anna M D Végh
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| | - Sjoerd N Duim
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| | - Anke M Smits
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| | - Robert E Poelmann
- Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands.
- Institute of Biology Leiden, Leiden University, Sylviusweg 20, 2311 EZ Leiden, The Netherlands.
| | - Arend D J Ten Harkel
- Department of Pediatric Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands.
| | - Marco C DeRuiter
- Department of Anatomy & Embryology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| | - Marie José Goumans
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands.
| | - Monique R M Jongbloed
- Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands.
- Department of Pediatric Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands.
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57
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Wang D, Liu T, Shi S, Li R, Shan Y, Huang Y, Hu D, Huang C. Chronic Administration of Catestatin Improves Autonomic Function and Exerts Cardioprotective Effects in Myocardial Infarction Rats. J Cardiovasc Pharmacol Ther 2016; 21:526-535. [PMID: 26821570 DOI: 10.1177/1074248416628676] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/28/2015] [Indexed: 12/20/2022]
Abstract
Catestatin (CST), which is emerging as a novel cardiac modulator, can protect the heart against excessive sympathetic drive in hypertensive cardiomyopathy. The aim of this study is to investigate whether exogenous CST decreases excessive cardiac sympathetic drive and improves autonomic function and exerts cardioprotective effects in myocardial infarction (MI) rats. Rats were divided into a sham group, MI group, and MI plus CST (MI + CST) group. Four weeks later, the autonomic function of the animals was assessed by analyzing heart rate variability (HRV) and measuring plasma catecholamine. Cardiac function was evaluated via echocardiography. Electrophysiological characteristics were assessed in Langendorff-perfused hearts. Compared to the MI group, the chronic administration of CST significantly increased the standard deviation of normal–normal intervals ( P < .01) and low-frequency (LF) and high-frequency (HF) HRV and decreased the ratio of LF–HF HRV ( P < .01 for all). Additionally, the level of plasma catecholamine was reduced in the MI + CST group compared to the MI group ( P < .01). Treatment with CST significantly increased ejection fraction (EF) and fraction shorting (FS) and significantly decreased the left ventricular end-systolic diameter and left ventricular end-diastolic diameter at 28 days postmyocardial infraction ( P < .05 for all). After MI, the ventricular repolarization duration, such as QTc intervals and action potential duration (APD) at 90% repolarization, was prolonged, and this prolongation could be decreased by CST ( P < .05 for all). The CST also increased the threshold of ADP alternans ( P < .01). Moreover, ventricular arrhythmias were induced in 83% of the MI group but only 33% of the MI + CST group ( P < .05). These results suggested that the chronic administration of CST plays a role in cardioprotection in MI rats, which may function by decreasing the cardiac sympathetic drive and improving autonomic function.
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Affiliation(s)
- Dandan Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Tao Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Shaobo Shi
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Ran Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Yingguang Shan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Yan Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
| | - Dan Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
- Masonic Medical Research Laboratory, Utica, NY, USA
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
- Cardiovacular Research Institute, Wuhan University, Wuhan, China
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58
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Ardell JL, Andresen MC, Armour JA, Billman GE, Chen PS, Foreman RD, Herring N, O'Leary DS, Sabbah HN, Schultz HD, Sunagawa K, Zucker IH. Translational neurocardiology: preclinical models and cardioneural integrative aspects. J Physiol 2016; 594:3877-909. [PMID: 27098459 DOI: 10.1113/jp271869] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/14/2016] [Indexed: 12/15/2022] Open
Abstract
Neuronal elements distributed throughout the cardiac nervous system, from the level of the insular cortex to the intrinsic cardiac nervous system, are in constant communication with one another to ensure that cardiac output matches the dynamic process of regional blood flow demand. Neural elements in their various 'levels' become differentially recruited in the transduction of sensory inputs arising from the heart, major vessels, other visceral organs and somatic structures to optimize neuronal coordination of regional cardiac function. This White Paper will review the relevant aspects of the structural and functional organization for autonomic control of the heart in normal conditions, how these systems remodel/adapt during cardiac disease, and finally how such knowledge can be leveraged in the evolving realm of autonomic regulation therapy for cardiac therapeutics.
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Affiliation(s)
- J L Ardell
- University of California - Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, CA, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, CA, USA
| | - M C Andresen
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR, USA
| | - J A Armour
- University of California - Los Angeles (UCLA) Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, CA, USA.,UCLA Neurocardiology Research Center of Excellence, David Geffen School of Medicine, Los Angeles, CA, USA
| | - G E Billman
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - P-S Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - R D Foreman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - N Herring
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - D S O'Leary
- Department of Physiology, Wayne State University, Detroit, MI, USA
| | - H N Sabbah
- Department of Medicine, Henry Ford Hospital, Detroit, MI, USA
| | - H D Schultz
- Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - K Sunagawa
- Department of Cardiovascular Medicine, Kyushu University, Fukuoka, Japan
| | - I H Zucker
- Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
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59
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Detailed heart rate variability analysis in athletes. Clin Auton Res 2016; 26:245-52. [DOI: 10.1007/s10286-016-0360-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 04/18/2016] [Indexed: 01/22/2023]
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Unraveling the role of high-intensity resistance training on left ventricle proteome: Is there a shift towards maladaptation? Life Sci 2016; 152:156-64. [PMID: 27021786 DOI: 10.1016/j.lfs.2016.03.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 03/13/2016] [Accepted: 03/21/2016] [Indexed: 01/08/2023]
Abstract
UNLABELLED High-intensity resistance training (RT) induces adaptations that improve physiological function. However, high intensity, volume and/or frequency may lead to injury and other health issues such as adverse cardiac effects. The aim of this study was to evaluate the effect of RT on left ventricle proteome, and to identify the pathways involved on the harmful adaptations induced by this protocol. Male Wistar rats were randomized into 2 groups: Trained (T) and Sedentary (S). Animals from T group were trained for 6weeks, and then all the animals were sacrificed and left ventricle was isolated for analysis. We identified 955 proteins, and 93 proteins were considered; 36 were expressed exclusively in T group, and 4 in S group. Based on quantitative analysis, 42 proteins were found overexpressed and 11 underexpressed in T group compared with S group. Using the Gene Ontology to relate the biological processes in which these proteins are involved, we conclude that RT protocol promotes changes similar to those found in the initial phase of heart failure, but we also observed a concomitant increased expression of protective proteins, suggesting the activation of pathways to avoid major damages on left ventricle and delay the onset of pathological hypertrophy. STATEMENT OF SIGNIFICANCE OF THE STUDY Our study shows that high-intensity RT protocol changes left ventricle proteome, modifying metabolic profile of heart tissue and inducing the expression of proteins that acts against cardiac injury. We hypothesize that these adaptations occur to prevent the onset of cardiac dysfunction. Despite highly significant, it remains to be determined whether these adaptations are sufficient to further keep left ventricle function and exert cardioprotection, and whether this panel will be shifted towards maladaptation, and heart failure.
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61
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Adámková V, Bělohoubek J, Adámek V, Juhaňáková M, Pirk J. Physical Activity and Exercise as a Basic Preventive Measure (Primary Prevention, Prevention after Renal Transplantation). Cent Eur J Public Health 2016; 23 Suppl:S3-8. [PMID: 26849540 DOI: 10.21101/cejph.a4014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 07/15/2015] [Indexed: 11/15/2022]
Abstract
Movement is an inseparable part of one's life, and has been a basic everyday activity through the history of mankind. However, a lack of physical activity and availability of food have resulted in a variety of serious health impairments. The 20th century has witnessed a steep rise of mortality from cardiovascular disease, increase in the prevalence of type-2 diabetes mellitus, malignant diseases, and dramatic increase in body weight initially in industrialized nations followed, in the last two decades of the last century, by the populations of third-world countries with all inherent consequences of this phenomenon. Preventive programmes involving physical activity have also been on the list of top priorities of various materials issued by the World Health Organization. Physical activity is one of the simplest non-pharmacological tools in the prevention of a plethora of diseases. The simplest physical activity, even for therapeutic purposes, is walking. We can walk any time, virtually anywhere, so walking is also the least expensive therapeutic option.
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Affiliation(s)
- Věra Adámková
- Institute for Clinical and Experimental Medicine, Department of Preventive Cardiology, Prague, Czech Republic
| | - Jiří Bělohoubek
- Institute for Clinical and Experimental Medicine, Department of Preventive Cardiology, Prague, Czech Republic
| | - Václav Adámek
- School of Biomedical Engineering, Czech Technical University, Kladno, Czech Republic
| | - Martina Juhaňáková
- Institute for Clinical and Experimental Medicine, Department of Preventive Cardiology, Prague, Czech Republic
| | - Jan Pirk
- Institute for Clinical and Experimental Medicine, Department of Preventive Cardiology, Prague, Czech Republic
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62
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Canan BD, Haizlip KM, Xu Y, Monasky MM, Hiranandani N, Milani-Nejad N, Varian KD, Slabaugh JL, Schultz EJ, Fedorov VV, Billman GE, Janssen PML. Effect of exercise training and myocardial infarction on force development and contractile kinetics in isolated canine myocardium. J Appl Physiol (1985) 2016; 120:817-24. [PMID: 26823341 DOI: 10.1152/japplphysiol.00775.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/27/2016] [Indexed: 12/20/2022] Open
Abstract
It is well known that moderate exercise training elicits a small increase in ventricular mass (i.e., a physiological hypertrophy) that has many beneficial effects on overall cardiac health. It is also well known that, when a myocardial infarction damages part of the heart, the remaining myocardium remodels to compensate for the loss of viable functioning myocardium. The effects of exercise training, myocardial infarction (MI), and their interaction on the contractile performance of the myocardium itself remain largely to be determined. The present study investigated the contractile properties and kinetics of right ventricular myocardium isolated from sedentary and exercise trained (10-12 wk progressively increasing treadmill running, begun 4 wk after MI induction) dogs with and without a left ventricular myocardial infarction. Exercise training increased force development, whereas MI decreased force development that was not improved by exercise training. Contractile kinetics were significantly slower in the trained dogs, whereas this impact of training was less or no longer present after MI. Length-dependent activation, both evaluated on contractile force and kinetics, was similar in all four groups. The control exercise-trained group exhibited a more positive force-frequency relationship compared with the sedentary control group while both sedentary and trained post-MI dogs had a more negative relationship. Last, the impact of the β-adrenergic receptor agonist isoproterenol resulted in a similar increase in force and acceleration of contractile kinetics in all groups. Thus, exercise training increased developed force but slowed contractile kinetics in control (noninfarcted animals), actions that were attenuated or completely absent in post-MI dogs.
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Affiliation(s)
- Benjamin D Canan
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Kaylan M Haizlip
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Ying Xu
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Michelle M Monasky
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Nitisha Hiranandani
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Nima Milani-Nejad
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Kenneth D Varian
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Jessica L Slabaugh
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Eric J Schultz
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - George E Billman
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; and Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio
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63
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Garatachea N, Pareja-Galeano H, Sanchis-Gomar F, Santos-Lozano A, Fiuza-Luces C, Morán M, Emanuele E, Joyner MJ, Lucia A. Exercise attenuates the major hallmarks of aging. Rejuvenation Res 2016; 18:57-89. [PMID: 25431878 DOI: 10.1089/rej.2014.1623] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Regular exercise has multi-system anti-aging effects. Here we summarize how exercise impacts the major hallmarks of aging. We propose that, besides searching for novel pharmaceutical targets of the aging process, more research efforts should be devoted to gaining insights into the molecular mediators of the benefits of exercise and to implement effective exercise interventions for elderly people.
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Affiliation(s)
- Nuria Garatachea
- 1 Faculty of Health and Sport Science, University of Zaragoza , Huesca, Spain
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64
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Pilot Randomized Study of a Gratitude Journaling Intervention on Heart Rate Variability and Inflammatory Biomarkers in Patients With Stage B Heart Failure. Psychosom Med 2016; 78:667-76. [PMID: 27187845 PMCID: PMC4927423 DOI: 10.1097/psy.0000000000000316] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Stage B, asymptomatic heart failure (HF) presents a therapeutic window for attenuating disease progression and development of HF symptoms, and improving quality of life. Gratitude, the practice of appreciating positive life features, is highly related to quality of life, leading to development of promising clinical interventions. However, few gratitude studies have investigated objective measures of physical health; most relied on self-report measures. We conducted a pilot study in Stage B HF patients to examine whether gratitude journaling improved biomarkers related to HF prognosis. METHODS Patients (n = 70; mean [standard deviation] age = 66.2 [7.6] years) were randomized to an 8-week gratitude journaling intervention or treatment as usual. Baseline (T1) assessments included the six-item Gratitude Questionnaire, resting heart rate variability (HRV), and an inflammatory biomarker index. At T2 (midintervention), the six-item Gratitude Questionnaire was measured. At T3 (postintervention), T1 measures were repeated but also included a gratitude journaling task. RESULTS The gratitude intervention was associated with improved trait gratitude scores (F = 6.0, p = .017, η = 0.10), reduced inflammatory biomarker index score over time (F = 9.7, p = .004, η = 0.21), and increased parasympathetic HRV responses during the gratitude journaling task (F = 4.2, p = .036, η = 0.15), compared with treatment as usual. However, there were no resting preintervention to postintervention group differences in HRV (p values > .10). CONCLUSIONS Gratitude journaling may improve biomarkers related to HF morbidity, such as reduced inflammation; large-scale studies with active control conditions are needed to confirm these findings. TRIAL REGISTRATION Clinicaltrials.govidentifier:NCT01615094.
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Volterrani M, Iellamo F. Cardiac Rehabilitation in Patients With Heart Failure: New Perspectives in Exercise Training. Card Fail Rev 2016; 2:63-68. [PMID: 28785455 DOI: 10.15420/cfr.2015:26:1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exercise training is recommended to patients with chronic heart failure (CHF) and reduced ejection fraction at a class 1 evidence level. Currently the 'dose' of exercise (dose being both volume and intensity) still remains uncertain and the best form of aerobic exercise training has not been defined. Guidelines commonly use heart rate (HR) as a target factor for both moderate continuous and interval training exercises. However, exercise training guided by HR can be limited in CHF patients due to chronotropic incompetence and beta-blocker treatment. In our study, we systematically addressed the above issues by applying a training method that takes into account both the volume and intensity of exercise on an individual basis. This method is referred to as individual TRaining IMPulses (TRIMPi). In this review, we summarise a series of investigations that used TRIMPi and different exercise forms to quantify the optimum training load in CHF patients. This review also highlights the way TRIMPi and the individual exercise dose affects cardiorespiratory, metabolic and autonomic cardiac adaptations.
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Affiliation(s)
| | - Ferdinando Iellamo
- Research Institute San Raffaele Pisana, Rome, Italy.,University of Rome Tor Vergata, Rome, Italy
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Jorat M, Raafat S, Ansari Z, Mahdavi-Anari L, Ghanbari-Firoozabadi M. The Impact of Hospital-Based Cardiac Rehabilitation on Signal Average ECG Parameters of the Heart After Myocardial Infarction. Res Cardiovasc Med 2015; 4:e26353. [PMID: 26448915 PMCID: PMC4592540 DOI: 10.5812/cardiovascmed.26353v2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 04/11/2015] [Accepted: 04/19/2015] [Indexed: 11/17/2022] Open
Abstract
Background: Cardiac rehabilitation is a combination of integrated programs aimed at improving outcomes in patients recovering from heart events. Objectives: The present study aimed to evaluate the early benefits of supervised exercise training on electrophysiological function of post-ischemic myocardium. In this regard, signal-averaged electrocardiogram (SAECG) was used. Patients and Methods: Between May and September 2012, all patients (n = 100) admitted to our center, with the diagnosis of acute Myocardial Infarction (MI), were enrolled in this study. Every other patient was assigned to two groups receiving either inpatient cardiac rehabilitation plus standard post-MI care (cases) or only standard post-MI care (controls). Electrophysiological function was assessed by SAECG in all the patients at baseline and on the day 5. The patients were considered as having late potential if they had abnormalities in at least two SAECG indices. Results: Cardiac rehabilitation led to significant improvements in QRS duration (P < 0.001), square root of amplitude in the last 40 ms (P < 0.001) and duration of terminal signal with low amplitude (P < 0.001). Cardiac rehabilitation also resulted in amelioration of SAECG parameters; frequency of patients with late potential significantly decreased from 64% to 20% after five days (P < 0.001). Conclusions: Supervised in-hospital exercise training was associated with improvements in SAECG-measured electrical activity post-MI.
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Affiliation(s)
- Mohammadvahid Jorat
- Cardiovascular Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Sina Raafat
- Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran
| | - Zahra Ansari
- Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran
- Corresponding author: Zahra Ansari, Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran. Fax: +98-3535253335, E-mail:
| | - Leila Mahdavi-Anari
- Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran
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67
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Tian Y, Huang C, He Z, Hong P, Zhao J. Autonomic function responses to training: Correlation with body composition changes. Physiol Behav 2015; 151:308-13. [PMID: 26253213 DOI: 10.1016/j.physbeh.2015.07.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 07/19/2015] [Accepted: 07/30/2015] [Indexed: 11/30/2022]
Abstract
AIM The causal relation between autonomic function and adiposity is an unresolved issue. Thus, we studied whether resting heart rate variability (HRV) changes could be used to predict changes in body composition after 16 weeks of individualized exercise training. METHODS A total of 117 sedentary overweight/obese adults volunteered to join an intervention group (IN, n=82) or a control group (CON, n=35). The intervention group trained for 30-40 min three times a week with an intensity of 85-100% of individual ventilatory threshold (Thvent). At baseline and after a 16-week training period, resting HRV variables, body composition and peak oxygen uptake (VO2peak) were assessed. RESULTS Compared with CON, exercise training significantly improved HRV and body composition and increased VO2peak (P<0.05). Significant correlations were observed between changes of HRV variables and body composition indices and VO2peak (P<0.05). Greater individual changes in HRV in response to exercise training were observed for those with greater total and central fat loss. CONCLUSION Individual aerobic-based exercise training was for improving autonomic function and resting HRV responses to aerobic training is a potential indicator for adaptations to exercise training.
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Affiliation(s)
- Ye Tian
- China Institute of Sport Science, Beijing, China.
| | - Chuanye Huang
- Department of Sports Science, Shandong University of Sport, Shandong, China
| | - Zihong He
- China Institute of Sport Science, Beijing, China
| | - Ping Hong
- China Institute of Sport Science, Beijing, China
| | - Jiexiu Zhao
- China Institute of Sport Science, Beijing, China
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Machado-Vidotti HG, Mendes RG, Simões RP, Castello-Simões V, Catai AM, Borghi-Silva A. Cardiac autonomic responses during upper versus lower limb resistance exercise in healthy elderly men. Braz J Phys Ther 2015; 18:9-18. [PMID: 24675908 PMCID: PMC4183232 DOI: 10.1590/s1413-35552012005000140] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 07/29/2013] [Indexed: 02/07/2023] Open
Abstract
Objective To investigate the cardiac autonomic responses during upper versus lower limb
discontinuous resistance exercise (RE) at different loads in healthy older
men. Method Ten volunteers (65±1.2 years) underwent the one-repetition maximum
(1RM) test to determine the maximum load for the bench press and the leg
press. Discontinuous RE was initiated at a load of 10%1RM with subsequent
increases of 10% until 30%1RM, followed by increases of 5%1RM until
exhaustion. Heart rate (HR) and R-R interval were recorded at rest and for 4
minutes at each load applied. Heart rate variability (HRV) was analyzed in
5-min segments at rest and at each load in the most stable 2-min signal.
Results Parasympathetic indices decreased significantly in both exercises from 30%1RM
compared to rest (rMSSD: 20±2 to 11±3 and 29±5 to
12±2 ms; SD1: 15±2 to 8±1 and 23±4 to 7±1
ms, for upper and lower limb exercise respectively) and HR increased
(69±4 to 90±4 bpm for upper and 66±2 to 89±1 bpm
for lower). RMSM increased for upper limb exercise, but decreased for lower
limb exercise (28±3 to 45±9 and 34±5 to 14±3 ms,
respectively). In the frequency domain, the sympathetic (LF) and
sympathovagal balance (LF/HF) indices were higher and the parasympathetic
index (HF) was lower for upper limb exercise than for lower limb exercise
from 35% of 1RM. Conclusions Cardiac autonomic change occurred from 30% of 1RM regardless of RE limb.
However, there was more pronounced sympathetic increase and vagal decrease
for upper limb exercise than for lower limb exercise. These results provide
a basis for more effective prescription of RE to promote health in this
population.
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Affiliation(s)
| | - Renata G Mendes
- Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil
| | - Rodrigo P Simões
- Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil
| | - Viviane Castello-Simões
- Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil
| | - Aparecida M Catai
- Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil
| | - Audrey Borghi-Silva
- Sao Carlos School of Engineering, Universidade de Sao Paulo, Sao Carlos, SP, Brazil
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Crisafulli A, Mancardi D, Marongiu E, Rastaldo R, Penna C, Pagliaro P. Preconditioning cardioprotection and exercise performance: a radical point of view. SPORT SCIENCES FOR HEALTH 2015. [DOI: 10.1007/s11332-015-0225-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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70
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Billman GE, Cagnoli KL, Csepe T, Li N, Wright P, Mohler PJ, Fedorov VV. Exercise training-induced bradycardia: evidence for enhanced parasympathetic regulation without changes in intrinsic sinoatrial node function. J Appl Physiol (1985) 2015; 118:1344-55. [PMID: 25749448 PMCID: PMC4451292 DOI: 10.1152/japplphysiol.01111.2014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/28/2015] [Indexed: 01/17/2023] Open
Abstract
The mechanisms responsible for exercise-induced reductions in baseline heart rate (HR), known as training bradycardia, remain controversial. Therefore, changes in cardiac autonomic regulation and intrinsic sinoatrial nodal (SAN) rate were evaluated using dogs randomly assigned to either a 10- to 12-wk exercise training (Ex, n = 15) or an equivalent sedentary period (Sed, n = 10). Intrinsic HR was revealed by combined autonomic nervous system (ANS) blockade (propranolol + atropine, iv) before and after completion of the study. At the end of the study, SAN function was further evaluated by examining the SAN recovery time (SNRT) following rapid atrial pacing and the response to adenosine in anesthetized animals. As expected, both the response to submaximal exercise and baseline HR significantly (P < 0.01) decreased, and heart rate variability (HRV; e.g., high-frequency R-R interval variability) significantly (P < 0.01) increased in the Ex group but did not change in the Sed group. Atropine also induced significantly (P < 0.01) greater reductions in HRV in the Ex group compared with the Sed group; propranolol elicited similar HR and HRV changes in both groups. In contrast, neither intrinsic HR (Ex before, 141.2 ± 6.7; Ex after, 146.0 ± 8.0 vs. Sed before, 143.3 ± 11.1; Sed after, 141.0 ± 11.3 beats per minute), the response to adenosine, corrected SNRT, nor atrial fibrosis and atrial fibrillation inducibility differed in the Ex group vs. the Sed group. These data suggest that in a large-animal model, training bradycardia results from an enhanced cardiac parasympathetic regulation and not from changes in intrinsic properties of the SAN.
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Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and
| | - Kristen L Cagnoli
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Thomas Csepe
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Ning Li
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Patrick Wright
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and
| | - Peter J Mohler
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and Deaprtment of Internal Medicine, The Ohio State University, Columbus, Ohio
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and
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Sex differences in heart rate variability: a longitudinal study in international elite cross-country skiers. Eur J Appl Physiol 2015; 115:2107-14. [PMID: 26002403 DOI: 10.1007/s00421-015-3190-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/09/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE Exercise-related sudden cardiac deaths (SCD) occur with a striking male predominance. A higher sympathetic tone in men has been suggested as risk factor for SCD. Elite athletes have the highest risk for exercise-related SCD. We aimed to analyze the autonomic nervous system of elite cross-country skiers from Norway, Russia and Switzerland in supine position and after orthostatic challenge in various training periods (TP). METHOD Measurements of heart rate variability (HRV) were performed on a weekly basis over 1 year using an orthostatic challenge test with controlled breathing. Main outcome parameters were the high-frequency power in supine position (HFsupine) as marker of cardiac parasympathetic activity and the low-frequency/high-frequency power ratio after orthostatic challenge (LF/HFstand) as marker of cardiac sympathetic activation. Training intensity and duration were recorded daily and expressed as training strain. The training year was divided into three TPs. An average of weekly HRV measurements was calculated for each TP. RESULT Female (n = 19, VO2max 62.0 ± 4.6 ml kg(-1) min(-1), age 25.8 ± 4.3 years) and male (n = 16, VO2max 74.3 ± 6.3 ml kg(-1) min(-1), age 24.4 ± 4.2 years) athletes were included. Training strain was comparable between sexes (all p > 0.05) and changed between TPs (all p < 0.05) while no HRV parameters changed over time. There were no sex differences in HFsupine while the LF/HFstand was significantly higher in male athletes in all TPs. CONCLUSION For a comparable amount of training, male athletes showed constantly higher markers of sympathetic activity after a provocation maneuver. This may explain part of the male predominance in sports-related SCD.
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72
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Dores H, Freitas A, Malhotra A, Mendes M, Sharma S. The hearts of competitive athletes: An up-to-date overview of exercise-induced cardiac adaptations. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2015. [DOI: 10.1016/j.repce.2014.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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73
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Dores H, Freitas A, Malhotra A, Mendes M, Sharma S. The hearts of competitive athletes: An up-to-date overview of exercise-induced cardiac adaptations. Rev Port Cardiol 2015; 34:51-64. [DOI: 10.1016/j.repc.2014.07.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/31/2014] [Indexed: 11/27/2022] Open
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Essner A, Sjöström R, Ahlgren E, Gustås P, Edge-Hughes L, Zetterberg L, Hellström K. Comparison of Polar® RS800CX heart rate monitor and electrocardiogram for measuring inter-beat intervals in healthy dogs. Physiol Behav 2014; 138:247-53. [PMID: 25446208 DOI: 10.1016/j.physbeh.2014.10.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/28/2014] [Accepted: 10/30/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED The aim of the present study was to assess the criterion validity, relative reliability and level of agreement of Polar® RS800CX heart rate monitor measuring inter-beat intervals (IBIs), compared to simultaneously recorded electrocardiogram (ECG) in dogs. METHODS Five continuous minutes of simultaneously recorded IBIs from Polar® RS800CX and Cardiostore ECG in 11 adult healthy dogs maintaining standing position were analyzed. Polar® data was statistically compared to ECG data to assess for systematic differences between the methods. Three different methods for handling missing IBI data were used. Criterion validities were calculated by intraclass correlation coefficients (ICCs) and corresponding 95% confidence intervals (CIs). Relative reliabilities and levels of agreement were calculated by ICCs and the Bland and Altman analysis for repeated measurements per subject. RESULTS Correlation coefficients between IBI data from ECG and Polar® RS800CX varied between 0.73 and 0.84 depending on how missing values were handled. Polar® was over- and underestimating IBI data compared to ECG. The mean difference in log transformed (base10) IBI data was 0.8%, and 93.2% of the values were within the limits of agreement. Internally excluding three subjects presenting IBI series containing more than 5% erroneous IBIs resulted in ICCs between 0.97 and 0.99. Bland and Altman analysis (n=8) showed mean difference was 1.8ms, and 98.5% of the IBI values were plotted inside limits of agreement. CONCLUSION This study showed that Polar® systematically biased recorded IBI series and that it was fundamental to detect measurement errors. For Polar® RS800CX heart rate monitor to be used interchangeably to ECG, by showing excellent criterion validity and reliable IBI measures in group and individual samples, only less than 5% of artifacts could be accepted.
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Affiliation(s)
- Ann Essner
- Uppsala University, Department of Neuroscience, Uppsala, Sweden; Evidensia Djurkliniken Gefle, Gävle, Sweden.
| | - Rita Sjöström
- Strömsund Health Centre, Jämtland County Council, Strömsund, Sweden; Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | | | - Pia Gustås
- Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Lena Zetterberg
- Uppsala University, Department of Neuroscience, Uppsala, Sweden
| | - Karin Hellström
- Uppsala University, Department of Neuroscience, Uppsala, Sweden
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Marongiu E, Crisafulli A. Cardioprotection acquired through exercise: the role of ischemic preconditioning. Curr Cardiol Rev 2014; 10:336-48. [PMID: 24720421 PMCID: PMC4101198 DOI: 10.2174/1573403x10666140404110229] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 12/16/2013] [Accepted: 03/28/2014] [Indexed: 02/07/2023] Open
Abstract
A great bulk of evidence supports the concept that regular exercise training can reduce the incidence of coronary events and increase survival chances after myocardial infarction. These exercise-induced beneficial effects on the myocardium are reached by means of the reduction of several risk factors relating to cardiovascular disease, such as high cholesterol, hypertension, obesity etc. Furthermore, it has been demonstrated that exercise can reproduce the "ischemic preconditioning" (IP), which refers to the capacity of short periods of ischemia to render the myocardium more resistant to subsequent ischemic insult and to limit infarct size during prolonged ischemia. However, IP is a complex phenomenon which, along with infarct size reduction, can also provide protection against arrhythmia and myocardial stunning due to ischemia-reperfusion. Several clues demonstrate that preconditioning may be directly induced by exercise, thus inducing a protective phenotype at the heart level without the necessity of causing ischemia. Exercise appears to act as a physiological stress that induces beneficial myocardial adaptive responses at cellular level. The purpose of the present paper is to review the latest data on the role played by exercise in triggering myocardial preconditioning.
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76
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Hepatocyte growth factor modification enhances the anti-arrhythmic properties of human bone marrow-derived mesenchymal stem cells. PLoS One 2014; 9:e111246. [PMID: 25360679 PMCID: PMC4216066 DOI: 10.1371/journal.pone.0111246] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 09/17/2014] [Indexed: 12/15/2022] Open
Abstract
Background/Aims Chronic myocardial infarction (MI) results in the formation of arrhythmogenic substrates, causing lethal ventricular arrhythmia (VA). We aimed to determine whether mesenchymal stem cells (MSCs) carrying a hepatocyte growth factor (HGF) gene modification (HGF-MSCs) decrease the levels of arrhythmogenic substrates and reduce the susceptibility to developing VA compared with unmodified MSCs and PBS in a swine infarction model. Methods The left descending anterior artery was balloon-occluded to establish an MI model. Four weeks later, the randomly grouped pigs were administered MSCs, PBS or HGF-MSCs via thoracotomy. After an additional four weeks, dynamic electrocardiography was performed to assess heart rate variability, and programmed electrical stimulation was conducted to evaluate the risk for VA. Then, the pigs were euthanized for morphometric, immunofluorescence and western blot analyses. Results: The HGF-MSC group displayed the highest vessel density and Cx43 expression levels, and the lowest levels of apoptosis, and tyrosine hydroxylase (TH) and growth associated protein 43 (GAP43) expression. Moreover, the HGF-MSC group exhibited a decrease in the number of sympathetic nerve fibers, substantial decreases in the low frequency and the low-/high- frequency ratio and increases in the root mean square of successive differences (rMSSD) and the percentage of successive normal sinus R-R intervals longer than 50 ms (pNN50), compared with the other two groups. Finally, the HGF-MSC group displayed the lowest susceptibility to developing VA. Conclusion HGF-MSCs displayed potent antiarrhythmic effects, reducing the risk for VA.
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Zhang F, Song G, Li X, Gu W, Shen Y, Chen M, Yang B, Qian L, Cao K. Transplantation of iPSc ameliorates neural remodeling and reduces ventricular arrhythmias in a post-infarcted swine model. J Cell Biochem 2014; 115:531-9. [PMID: 24122925 DOI: 10.1002/jcb.24687] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/26/2013] [Indexed: 12/14/2022]
Abstract
Neural remodeling after myocardial infarction (MI) may cause malignant ventricular arrhythmia, which is the main cause of sudden cardiac death following MI. Herein, we aimed to examine whether induced pluripotent stem cells (iPSc) transplantation can ameliorate neural remodeling and reduce ventricular arrhythmias (VA) in a post-infarcted swine model. Left anterior descending coronary arteries were balloon-occluded to generate MI. Animals were then divided into Sham, PBS control, and iPS groups. Dynamic electrocardiography programmed electric stimulation were performed to evaluate VA. The spatial distribution of vascularization, Cx43 and autonomic nerve regeneration were evaluated by immunofluorescence staining. Associated protein expression was detected by Western blotting. Likewise, we measured the enzymatic activities of superoxide dismutase and content of malondialdehyde. Six weeks later, the number of blood vessels increased significantly in the iPSc group. The expression of vascular endothelial growth factor and connexin 43 in the iPS group was significantly higher than the PBS group; however, the levels of nerve growth factor and tyrosine hydroxylase were lower. The oxidative stress was ameliorated by iPSc transplantation. Moreover, the number of sympathetic nerves in the iPSc group was reduced, while the parasympathetic nerve fibers had no obvious change. The transplantation of iPSc also significantly decreased the low-/high-frequency ratio and arrhythmia score of programmed electric stimulation-induced VA. In conclusion, iPSc intramyocardial transplantation reduces vulnerability to VAs, and the mechanism was related to the remodeling amelioration of autonomic nerves and gap junctions. Moreover, possible mechanisms of iPSc transplantation in improving neural remodeling may be related to attenuated oxidative stress and inflammatory response.
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Affiliation(s)
- Fengxiang Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, People's Republic of China
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Yamada Y, Kinoshita H, Kuwahara K, Nakagawa Y, Kuwabara Y, Minami T, Yamada C, Shibata J, Nakao K, Cho K, Arai Y, Yasuno S, Nishikimi T, Ueshima K, Kamakura S, Nishida M, Kiyonaka S, Mori Y, Kimura T, Kangawa K, Nakao K. Inhibition of N-type Ca2+ channels ameliorates an imbalance in cardiac autonomic nerve activity and prevents lethal arrhythmias in mice with heart failure. Cardiovasc Res 2014; 104:183-93. [DOI: 10.1093/cvr/cvu185] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yapari F, Deshpande D, Belhamadia Y, Dubljevic S. Control of cardiac alternans by mechanical and electrical feedback. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:012706. [PMID: 25122334 DOI: 10.1103/physreve.90.012706] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Indexed: 06/03/2023]
Abstract
A persistent alternation in the cardiac action potential duration has been linked to the onset of ventricular arrhythmia, which may lead to sudden cardiac death. A coupling between these cardiac alternans and the intracellular calcium dynamics has also been identified in previous studies. In this paper, the system of PDEs describing the small amplitude of alternans and the alternation of peak intracellular Ca(2+) are stabilized by optimal boundary and spatially distributed actuation. A simulation study demonstrating the successful annihilation of both alternans on a one-dimensional cable of cardiac cells by utilizing the full-state feedback controller is presented. Complimentary to these studies, a three variable Nash-Panfilov model is used to investigate alternans annihilation via mechanical (or stretch) perturbations. The coupled model includes the active stress which defines the mechanical properties of the tissue and is utilized in the feedback algorithm as an independent input from the pacing based controller realization in alternans annihilation. Simulation studies of both control methods demonstrate that the proposed methods can successfully annihilate alternans in cables that are significantly longer than 1 cm, thus overcoming the limitations of earlier control efforts.
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Affiliation(s)
- Felicia Yapari
- Deparment of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 Canada
| | - Dipen Deshpande
- Deparment of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 Canada
| | - Youssef Belhamadia
- Campus Saint-Jean and Department of Mathematics, University of Alberta, Edmonton, Alberta, T6C 4G9 Canada
| | - Stevan Dubljevic
- Deparment of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 Canada
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Ruiz JR, Joyner M, Lucia A. CrossTalk opposing view: Prolonged intense exercise does not lead to cardiac damage. J Physiol 2014; 591:4943-5. [PMID: 24130314 DOI: 10.1113/jphysiol.2013.257147] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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81
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European guidelines on cardiovascular disease prevention in clinical practice (version 2012) : the fifth joint task force of the European society of cardiology and other societies on cardiovascular disease prevention in clinical practice (constituted by representatives of nine societies and by invited experts). Int J Behav Med 2014; 19:403-88. [PMID: 23093473 DOI: 10.1007/s12529-012-9242-5] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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82
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Effects of individualized exercise training in patients with catecholaminergic polymorphic ventricular tachycardia type 1. Am J Cardiol 2014; 113:1829-33. [PMID: 24837260 DOI: 10.1016/j.amjcard.2014.03.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 11/23/2022]
Abstract
Ventricular arrhythmias (VAs) in patients with catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) are triggered at an individual and reproducible heart rate (HR) during exercise. Long-term effects of exercise on arrhythmia threshold in CPVT1 are not known. To investigate whether exercise training (ET) is feasible in patients with CPVT1, 13 patients with CPVT1 and confirmed genetic mutations performed bicycle exercise testing with maximal oxygen uptake (VO2max) measurements at baseline and after 13 weeks. The threshold HR for VA was defined as the HR when bigeminal ventricular extrasystoles or more severe VAs occurred. Six patients were enrolled in a 12-week high-intensity ergometer bicycle ET program (ET patients) with 60 min exercise sessions 3 times per week. The remaining 7 patients with CPVT1 were included as "sedentary" control (SED) patients complying with current recommendations to restrain from high-intensity physical activity. ET patients completed 28 ± 3 exercise sessions (78 ± 8% program completion) with 13 ± 3% increase in VO2max versus baseline (20.2 ± 1.6 vs 17.9 ± 1.3 ml/kg/min, p <0.05). No adverse events occurred. Baseline threshold for VA was 100 ± 6 beats/min in ET patients and 135 ± 4 beats/min in SED patients. After the training period, threshold HR for VA was 111 ± 10 beats/min in ET patients and 123 ± 6 beats/min in SED patients. The threshold for VA increased in ET compared with SED patients (+11 vs -12 beats/min, p <0.05). In conclusion, patients with CPVT1 benefitted from individualized ET with improved aerobic capacity and increased threshold HR for VA compared with SED patients.
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Chen T, Cai MX, Li YY, He ZX, Shi XC, Song W, Wang YH, Xi Y, Kang YM, Tian ZJ. Aerobic exercise inhibits sympathetic nerve sprouting and restores β-adrenergic receptor balance in rats with myocardial infarction. PLoS One 2014; 9:e97810. [PMID: 24842290 PMCID: PMC4026473 DOI: 10.1371/journal.pone.0097810] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/24/2014] [Indexed: 12/24/2022] Open
Abstract
Background Cardiac sympathetic nerve sprouting and the dysregulation of β-adrenergic receptor (β-AR) play a critical role in the deterioration of cardiac function after myocardial infarction (MI). Growing evidence indicates that exercise provides protection against MI. The aims of this study were to investigate whether aerobic exercise following MI could inhibit sympathetic nerve sprouting and restore the balance of β3-AR/β1-AR. Methods Male Sprague-Dawley rats were divided into three groups: sham-operated control group (SC), MI group (MI), and MI with aerobic exercise group (ME). The rats in ME group were assigned to 8 weeks of exercise protocol (16 m/min, 50 min/d, 5 d/wk). The expression of nerve growth factor (NGF), the sympathetic nerve marker-tyrosine hydroxylase (TH), the nerve sprouting marker-growth associated protein 43 (GAP43), and β1- and β2-AR expression in the peri-infarct area of the left ventricle (LV) were measured by Western blot and immunohistochemistry, while β3-AR expression was determined by Western blot and immunofluorescence. Endothelial nitric oxide synthase (NOS2), phospho-NOS2 (p-NOS2), and neuronal nitric oxide synthase (NOS1) were measured by Western blot. Results MI increased LV end-diastolic pressure (LVEDP), and decreased LV systolic pressure (LVSP). Compared with the MI group, aerobic exercise significantly decreased LVEDP and increased LVSP. The protein expression of TH, GAP43 and NGF was significantly increased after MI, which was normalized by exercise. Compared with the SC group, the ratios of β2-AR/β1-AR and β3-AR/β1-AR were elevated in the MI group, and the protein expression of β3-AR and NOS1 increased after MI. Compared with the MI group, the ratios of β2-AR/β1-AR and β3-AR/β1-AR were normalized in the ME group, while the protein expression of β3-AR and NOS1 significantly increased, and NOS2 was activated by exercise. Conclusions Aerobic exercise inhibits cardiac sympathetic nerve sprouting, restores β3-AR/β1-AR balance and increases β3-AR expression through the activation of NOS2 and NOS1 after myocardial infarction.
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Affiliation(s)
- Ting Chen
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
- Department of Sports and Exercise, Tibet University for Nationalities, Xian yang, Shaanxi, P. R. China
| | - Meng-Xin Cai
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - You-You Li
- Department of Physiology and Department of Cardiology, Fourth Military Medical University, Xi’an, Shaanxi, P. R. China
| | - Zhi-Xiong He
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - Xiu-Chao Shi
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - Wei Song
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - You-Hua Wang
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - Yue Xi
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Xi’an Jiaotong University Cardiovascular Research Center, Xi’an Jiaotong University School of Medicine, Xi’an, Shaanxi, P. R. China
| | - Zhen-Jun Tian
- Institute of Sports and Exercise Biology, Shaanxi Normal University, Xi’an, Shaanxi, P. R. China
- * E-mail:
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Soares-Miranda L, Sattelmair J, Chaves P, Duncan GE, Siscovick DS, Stein PK, Mozaffarian D. Physical activity and heart rate variability in older adults: the Cardiovascular Health Study. Circulation 2014; 129:2100-10. [PMID: 24799513 DOI: 10.1161/circulationaha.113.005361] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults. METHODS AND RESULTS We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincaré ratio (Ptrend=0.02), markers of less erratic sinus patterns. CONCLUSIONS Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life.
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Affiliation(s)
- Luisa Soares-Miranda
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
| | - Jacob Sattelmair
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
| | - Paulo Chaves
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
| | - Glen E Duncan
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
| | - David S Siscovick
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
| | - Phyllis K Stein
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
| | - Dariush Mozaffarian
- From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.)
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Okuno NM, Pedro RE, Leicht AS, de Paula Ramos S, Nakamura FY. Cardiac Autonomic Recovery After a Single Session of Resistance Exercise With and Without Vascular Occlusion. J Strength Cond Res 2014; 28:1143-50. [PMID: 24077384 DOI: 10.1519/jsc.0000000000000245] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nilo M Okuno
- 1Department of Physical Education, State University of Ponta Grossa, Ponta Grossa, Brazil; 2Department of Physical Education, State University of Londrina, Londrina, Brazil; 3Institute of Sport and Exercise Science, James Cook University, Townsville, Australia; and 4Department of Histology, State University of Londrina, Londrina, Brazil
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87
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Fiuza-Luces C, Garatachea N, Berger NA, Lucia A. Exercise is the real polypill. Physiology (Bethesda) 2014; 28:330-58. [PMID: 23997192 DOI: 10.1152/physiol.00019.2013] [Citation(s) in RCA: 325] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The concept of a "polypill" is receiving growing attention to prevent cardiovascular disease. Yet similar if not overall higher benefits are achievable with regular exercise, a drug-free intervention for which our genome has been haped over evolution. Compared with drugs, exercise is available at low cost and relatively free of adverse effects. We summarize epidemiological evidence on the preventive/therapeutic benefits of exercise and on the main biological mediators involved.
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88
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Barnes JN, Joyner MJ. Physical activity and cardiovascular risk: 10 metabolic equivalents or bust. Mayo Clin Proc 2013; 88:1353-5. [PMID: 24290107 DOI: 10.1016/j.mayocp.2013.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 10/23/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Jill N Barnes
- Department of Anesthesiology, Mayo Clinic, Rochester, MN
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Iliescu R, Tudorancea I, Irwin ED, Lohmeier TE. Chronic baroreflex activation restores spontaneous baroreflex control and variability of heart rate in obesity-induced hypertension. Am J Physiol Heart Circ Physiol 2013; 305:H1080-8. [PMID: 23913707 PMCID: PMC3798752 DOI: 10.1152/ajpheart.00464.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/27/2013] [Indexed: 12/21/2022]
Abstract
The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation-current therapies in patients with resistant hypertension, who are commonly obese-restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1-4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and <20%, respectively, of control levels. Subsequently, both baroreflex activation and renal denervation abolished the hypertension. However, only baroreflex activation effectively attenuated the tachycardia and restored cardiac baroreflex sensitivity and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure.
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Affiliation(s)
- Radu Iliescu
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
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90
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Billman GE. The effect of heart rate on the heart rate variability response to autonomic interventions. Front Physiol 2013; 4:222. [PMID: 23986716 PMCID: PMC3752439 DOI: 10.3389/fphys.2013.00222] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 08/02/2013] [Indexed: 11/21/2022] Open
Abstract
Heart rate variability (HRV), the beat-to-beat variation in either heart rate (HR) or heart period (R-R interval), has become a popular clinical and investigational tool to quantify cardiac autonomic regulation. However, it is not widely appreciated that, due to the inverse curvilinear relationship between HR and R-R interval, HR per se can profoundly influence HRV. It is, therefore, critical to correct HRV for the prevailing HR particularly, as HR changes in response to autonomic neural activation or inhibition. The present study evaluated the effects of HR on the HRV response to autonomic interventions that either increased (submaximal exercise, n = 25 or baroreceptor reflex activation, n = 20) or reduced (pharmacological blockade: β-adrenergic receptor, muscarinic receptor antagonists alone and in combination, n = 25, or bilateral cervical vagotomy, n = 9) autonomic neural activity in a canine model. Both total (RR interval standard deviation, RRSD) and the high frequency (HF) variability (HF, 0.24–1.04 Hz) were determined before and in response to an autonomic intervention. All interventions that reduced or abolished cardiac parasympathetic regulation provoked large reductions in HRV even after HR correction [division by mean RRsec or (mean RRsec)2 for RRSD and HF, respectively] while interventions that reduced HR yielded mixed results. β-adrenergic receptor blockade reduced HRV (RRSD but not HF) while both RRSD and HF increased in response to increases in arterial blood (baroreceptor reflex activation) even after HR correction. These data suggest that the physiological basis for HRV is revealed after correction for prevailing HR and, further, that cardiac parasympathetic activity is responsible for a major portion of the HRV in the dog.
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Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University Columbus, OH, USA
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91
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The Lambeth Conventions (II): Guidelines for the study of animal and human ventricular and supraventricular arrhythmias. Pharmacol Ther 2013; 139:213-48. [DOI: 10.1016/j.pharmthera.2013.04.008] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 04/01/2013] [Indexed: 12/17/2022]
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Fletcher GF, Ades PA, Kligfield P, Arena R, Balady GJ, Bittner VA, Coke LA, Fleg JL, Forman DE, Gerber TC, Gulati M, Madan K, Rhodes J, Thompson PD, Williams MA. Exercise standards for testing and training: a scientific statement from the American Heart Association. Circulation 2013; 128:873-934. [PMID: 23877260 DOI: 10.1161/cir.0b013e31829b5b44] [Citation(s) in RCA: 1205] [Impact Index Per Article: 109.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Dor-Haim H, Berenfeld O, Horowitz M, Lotan C, Swissa M. Reduced Ventricular Arrhythmogeneity and Increased Electrical Complexity in Normal Exercised Rats. PLoS One 2013; 8:e66658. [PMID: 23825553 PMCID: PMC3688953 DOI: 10.1371/journal.pone.0066658] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/09/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The mechanisms whereby aerobic training reduces the occurrence of sudden cardiac death in humans are not clear. We test the hypothesis that exercise-induced increased resistance to ventricular tachycardia and fibrillation (VT/VF) involve an intrinsic remodeling in healthy hearts. METHODS AND RESULTS Thirty rats were divided into a sedentary (CTRL, n = 16) and two exercise groups: short- (4 weeks, ST, n = 7) and long-term (8 weeks, LT, n = 7) trained groups. Following the exercise program hearts were isolated and studied in a Langendorff perfusion system. An S1-S2 pacing protocol was applied at the right ventricle to determine inducibility of VT/VF. Fast Fourier transforms were applied on ECG time-series. In-vivo measurements showed training-induced increase in aerobic capacity, heart-to-body weight ratio and a 50% low-to-high frequency ratio reduction in the heart rate variability (p<0.05). In isolated hearts the probability for VF decreased from 26.1±14.4 in CTRL to 13.9±14.1 and 6.7±8.5% in the ST and LT, respectively (p<0.05). Duration of VF also decreased from 19.0±5.7 in CTRL to 8.8±7.1 and 6.0±5.8 sec in ST and LT respectively (p<0.05). Moreover, the pacing current required for VF induction increased following exercise (2.9±1.7 vs. 5.4±2.1 and 8.5±0.9 mA, respectively; p<0.05). Frequency analysis of ECG revealed an exercise-induced VF transition from a narrow single peak spectrum at 17 Hz in CTRL to a broader range of peaks ranging between 8.8 and 22.5 Hz in the LT group (p<0.05). CONCLUSION Exercise in rats leads to reduced VF propensity associated with an intrinsic cardiac remodeling related to a broader spectral range and faster frequency components in the ECG.
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Affiliation(s)
- Horesh Dor-Haim
- Heart Institute, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Omer Berenfeld
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michal Horowitz
- Department of Physiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Chaim Lotan
- Heart Institute, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Moshe Swissa
- Cardiac Research Center, Kaplan Medical Center, Rehovot, Israel
- * E-mail:
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94
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Billman GE. The effects of omega-3 polyunsaturated fatty acids on cardiac rhythm: a critical reassessment. Pharmacol Ther 2013; 140:53-80. [PMID: 23735203 DOI: 10.1016/j.pharmthera.2013.05.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 11/28/2022]
Abstract
Although epidemiological studies provide strong evidence for an inverse relationship between omega-3 polyunsaturated fatty acids (n-3 PUFAs) and cardiac mortality, inconsistent and often conflicting results have been obtained from both animal studies and clinical prevention trials. Despite these heterogeneous results, some general conclusions can be drawn from these studies: 1) n-PUFAs have potent effects on ion channels and calcium regulatory proteins that vary depending on the route of administration. Circulating (acute administration) n-3 PUFAs affect ion channels directly while incorporation (long-term supplementation) of these lipids into cell membranes indirectly alter cardiac electrical activity via alteration of membrane properties. 2) n-3 PUFAs reduce baseline HR and increase HRV via alterations in intrinsic pacemaker rate rather than from changes in cardiac autonomic neural regulation. 3) n-3 PUFAs may be only effective if given before electrophysiological or structural remodeling has begun and have no efficacy against atrial fibrillation. 5) Despite initial encouraging results, more recent clinical prevention and animal studies have not only failed to reduce sudden cardiac death but actually increased mortality in angina patients and increased rather than decreased malignant arrhythmias in animal models of regional ischemia. 6) Given the inconsistent benefits reported in clinical and experimental studies and the potential adverse actions on cardiac rhythm noted during myocardial ischemia, n-3 PUFA must be prescribed with caution and generalized recommendations to increase fish intake or to take n-3 PUFA supplements need to be reconsidered.
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Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University, 304 Hamilton Hall, 1645 Neil Ave., Columbus, OH 43210-1218, United States.
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Dungan KM, Osei K, Sagrilla C, Binkley P. Effect of the approach to insulin therapy on glycaemic fluctuations and autonomic tone in hospitalized patients with diabetes. Diabetes Obes Metab 2013; 15:558-63. [PMID: 23350696 PMCID: PMC3644350 DOI: 10.1111/dom.12069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 12/27/2012] [Accepted: 01/20/2013] [Indexed: 11/27/2022]
Abstract
AIMS Glycaemic variability (GV) is associated with mortality in acutely ill patients, but the mechanism is unknown. The objective of this study is to determine whether common approaches to insulin therapy have distinct effects on GV and autonomic tone. METHODS Hospitalized patients with diabetes were randomized to short-term intravenous (IV) or physiologic subcutaneous (SQ) insulin. Heart rate variability (HRV) and cardiac impedance (pre-ejection period, PEP) were used to estimate parasympathetic and sympathetic tone, respectively. GV was measured using a continuous glucose monitor. RESULTS Mean glucose tended to be lower initially in the SQ group (N = 16) compared with the IV group (N = 17) on day 1 (10.5 vs. 8.6 mmol/l, p = 0.05), but became non-significant during the transition off of the infusion. There was no difference in glycaemic lability index (GLI), continuous overlapping net glycaemic action (CONGA) or coefficient of variation (CV) on day 1, but by day 2, these measures were higher in the IV group (p < 0.05 for all). PEP was higher in the SQ group during (110 vs. 123 ms, p = 0.02) and after the intervention (104 vs. 126 ms, p = 0.004). Hypoglycaemia was similar in both groups. There were only small differences in HRV. Post-treatment PEP was inversely correlated with log GLI (r = -0.41, p = 0.03) but not other measures. CONCLUSIONS Short-term IV insulin is associated with an increase in multiple GV measures compared with optimal SQ insulin. However, GLI was the only predictor of PEP. Further research is needed to determine if interventions that minimize GV improve outcomes in the hospital.
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Affiliation(s)
- K M Dungan
- Division of Endocrinology, Diabetes & Metabolism, The Ohio State University, Columbus, OH 43210-1296, USA.
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Moraes OA, Colucci JA, Souza LE, Scapini KB, Moraes-Silva IC, Mostarda C, De Angelis K, Casarini DE, Irigoyen MC. Cardiovascular autonomic dysfunction in non-obese diabetic mice. Auton Neurosci 2013; 177:143-7. [PMID: 23622812 DOI: 10.1016/j.autneu.2013.03.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 03/18/2013] [Accepted: 03/27/2013] [Indexed: 11/28/2022]
Abstract
It is known that diabetes is associated with autonomic dysfunction; however, data about autonomic function in non-obese diabetic mice (NOD) remain scarce. We evaluated the autonomic profile of NOD mice. Female mice, 24-28 week old, were divided in two groups: NOD (n = 6) and control (n = 6, Swiss mice). NOD mice with glycemia ≥ 300 mg/dl were used. Heart rate variability (HRV) and arterial pressure variability (APV) in time and frequency domains, symbolic analysis of heart rate (HR) and baroreflex sensitivity were evaluated. HR and arterial pressure (AP) were similar between the groups; however, HRV (total variance of RR interval: NOD=21.07 ± 3.75 vs. C = 42.02 ± 6.54 ms(2)) and the vagal modulation index RMSSD were lower in NOD group (4.01 ± 0.32 vs. 8.28 ± 0.97 ms). Moreover, the absolute and normalized low-frequency (LF) components were also enhanced in NOD (normalized = 61.0 ± 4.0%) as compared to control mice (normalized = 20.0 ± 4.0%). Both the absolute and normalized high-frequency (HF) components were lower in NOD (normalized = 39.0 ± 4.0%) when compared to the control group (normalized = 80.0 ± 4.0). In the symbolic analysis the 0V pattern, an indication of sympathetic activity, was higher in NOD and 2 LV pattern, an indication of parasympathetic activity, was lower in the NOD than in the control group. Both bradycardic and tachycardic responses were decreased in NOD (3.01 ± 0.72 vs. 4.54 ± 0.36 bpm/mmHg and 2.49 ± 0.31 vs. C = 3.43 ± 0.33 bpm/mmHg) when compared to the control group. Correlation analysis showed negative correlations between vagal indexes (RMSSD, %HF and 2LV) and glycemic levels. In conclusion, NOD mice develop severe diabetes correlated with autonomic dysfunction.
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Affiliation(s)
- Oscar A Moraes
- Hypertension Unit, Heart Institute (InCor), School of Medicine, University of São Paulo (FMUSP), 44 Dr Eneas de Carvalho Aguiar Avenue, 05403-000 São Paulo/SP, Brazil; Nove de Julho University, Sao Paulo/SP, Brazil.
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97
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Lan YF, Zhang JC, Gao JL, Wang XP, Fang Z, Fu YC, Chen MY, Lin M, Xue Q, Li Y. Effects of nerve growth factor on the action potential duration and repolarizing currents in a rabbit model of myocardial infarction. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2013; 10:39-51. [PMID: 23610573 PMCID: PMC3627714 DOI: 10.3969/j.issn.1671-5411.2013.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 09/11/2012] [Accepted: 01/18/2013] [Indexed: 01/08/2023]
Abstract
OBJECTIVES To investigate the effect of nerve growth factor (NGF) on the action potential and potassium currents of non-infarcted myocardium in the myocardial infarcted rabbit model. METHODS Rabbits with occlusion of the left anterior descending coronary artery were prepared and allowed to recover for eight weeks (healed myocardial infarction, HMI). During ligation surgery of the left coronary artery, a polyethylene tube was placed near the left stellate ganglion in the subcutis of the neck for the purpose of administering NGF 400 U/d for eight weeks (HMI + NGF group). Cardiomyocytes were isolated from regions of the non-infarcted left ventricular wall and the action potentials and ion currents in these cells were recorded using whole-cell patch clamps. RESULTS Compared with HMI and control cardiomyocytes, significant prolongation of APD50 or APD90 (Action potential duration (APD) measured at 50% and 90% of repolarization) in HMI + NGF cardiomyocytes was found. The results showed that the 4-aminopyridine sensitive transient outward potassium current (I to), the rapidly activated omponent of delayed rectifier potassium current (I Kr), the slowly activated component of delayed rectifier potassium current (I Ks), and the L-type calcium current (I CaL) were significantly altered in NGF + HMI cardiomyocytes compared with HMI and control cells. CONCLUSIONS Our results suggest that NGF treatment significantly prolongs APD in HMI cardiomyocytes and that a decrease in outward potassium currents and an increase of inward Ca(2+) current are likely the underlying mechanism of action.
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Affiliation(s)
- Yun-Feng Lan
- Institute of Geriatric Cardiology of Chinese PLA General Hospital, 28 Fuxing Road, 100853 Beijing, China
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98
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Billman GE. The LF/HF ratio does not accurately measure cardiac sympatho-vagal balance. Front Physiol 2013; 4:26. [PMID: 23431279 PMCID: PMC3576706 DOI: 10.3389/fphys.2013.00026] [Citation(s) in RCA: 696] [Impact Index Per Article: 63.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/02/2013] [Indexed: 11/13/2022] Open
Affiliation(s)
- George E Billman
- Department of Physiology and Cell Biology, The Ohio State University Columbus, OH, USA
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99
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Frasier CR, Moukdar F, Patel HD, Sloan RC, Stewart LM, Alleman RJ, La Favor JD, Brown DA. Redox-dependent increases in glutathione reductase and exercise preconditioning: role of NADPH oxidase and mitochondria. Cardiovasc Res 2013; 98:47-55. [PMID: 23341578 DOI: 10.1093/cvr/cvt009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIMS We have previously shown that exercise leads to sustainable cardioprotection through a mechanism involving improved glutathione replenishment. This study was conducted to determine if redox-dependent modifications in glutathione reductase (GR) were involved in exercise cardioprotection. Furthermore, we sought to determine if reactive oxygen species generated by NADPH oxidase and/or mitochondria during exercise were triggering events for GR modulations. METHODS AND RESULTS Rats were exercised for 10 consecutive days, after which isolated hearts were exposed to ischaemia/reperfusion (25 min/120 min). Exercise protected against infarction and arrhythmia, and preserved coronary flow. The GR inhibitor BCNU abolished the beneficial effects. GR activity was increased following exercise in a redox-dependent manner, with no change in GR protein levels. Because fluorescent labelling of GR protein thiols showed lower amounts of reduced thiols after exercise, we sought to determine the source of intracellular reactive oxygen species that may be activating GR. Subsets of animals were exercised immediately after treatment with either NADPH-oxidase inhibitors apocynin or Vas2870, or with mitoTEMPO or Bendavia, which reduce mitochondrial reactive oxygen species levels. The cardioprotective effects of exercise were abolished if animals exercised in the presence of NADPH oxidase inhibitors, in clear contrast to the mitochondrial reagents. These changes correlated with thiol-dependent modifications of GR. CONCLUSION Adaptive cardioprotective signalling is triggered by reactive oxygen species from NADPH oxidase, and leads to improved glutathione replenishment through redox-dependent modifications in GR.
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Affiliation(s)
- Chad R Frasier
- Department of Physiology, Brody 6N-98, 600 Moye Blvd, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
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100
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Lujan HL, DiCarlo SE. Cardiac output, at rest and during exercise, before and during myocardial ischemia, reperfusion, and infarction in conscious mice. Am J Physiol Regul Integr Comp Physiol 2013; 304:R286-95. [PMID: 23302959 DOI: 10.1152/ajpregu.00517.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Multiple systems and regulatory strategies interact to control cardiac homeostasis. In fact, regulated systems, feedback controls, and redundant control mechanisms dominate in whole animals. Accordingly, molecular and cellular tools and techniques must be utilized in complex models with multiple systems and regulatory strategies to fully appreciate the physiological context. Currently, these techniques are mainly performed under conditions remote from the normal in vivo condition; thus, the extrapolation of molecular changes to the in vivo situation and the facilitation of translational aspect of the findings are limited. A major obstacle has been the reliance on preparations that do not mimic the clinical or physiological situation. This is particularly true regarding measurements of cardiac function in mice. To address these concerns, we used a permanently implanted Doppler ultrasonic flow probe on the ascending aorta and coronary artery occluder for repeated measurements of ascending aortic blood flow (cardiac output) in conscious mice, at rest and during exercise, before and during coronary artery occlusion/reperfusion and infarction. The conscious mouse model permits detailed monitoring of within-animal changes in cardiac function during myocardial ischemia, reperfusion, and infarction in an intact, complex model free of the confounding influences of anesthetics, surgical trauma, and restraint stress. Results from this study suggest that previous protocols may have overestimated resting baseline values and underestimated cardiac output reserve. Using these procedures in currently available spontaneous or engineered mouse mutants has the potential to be of major importance for advancing the concepts and methods that drive cardiovascular research.
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Affiliation(s)
- Heidi L Lujan
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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