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D'Souza AW, Badrov MB, Wood KN, Lalande S, Suskin N, Shoemaker JK. The impact of 6 months of exercise-based cardiac rehabilitation on sympathetic neural recruitment during apneic stress. Am J Physiol Regul Integr Comp Physiol 2021; 321:R174-R185. [PMID: 34133229 DOI: 10.1152/ajpregu.00080.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The current study evaluated the hypothesis that 6 mo of exercise-based cardiac rehabilitation (CR) would improve sympathetic neural recruitment in patients with ischemic heart disease (IHD). Microneurography was used to evaluate action potential (AP) discharge patterns within bursts of muscle sympathetic nerve activity (MSNA), in 11 patients with IHD (1 female; 61 ± 9 yr) pre (pre-CR) and post (post-CR) 6 mo of aerobic and resistance training-based CR. Measures were made at baseline and during maximal voluntary end-inspiratory (EI-APN) and end-expiratory apneas (EE-APN). Data were analyzed during 1 min of baseline and the second half of apneas. At baseline, overall sympathetic activity was less post-CR (all P < 0.01). During EI-APN, AP recruitment was not observed pre-CR (all P > 0.05), but increases in both within-burst AP firing frequency (Δpre-CR: 2 ± 3 AP spikes/burst vs. Δpost-CR: 4 ± 3 AP spikes/burst; P = 0.02) and AP cluster recruitment (Δpre-CR: -1 ± 2 vs. Δpost-CR: 2 ± 2; P < 0.01) were observed in post-CR tests. In contrast, during EE-APN, AP firing frequency was not different post-CR compared with pre-CR tests (Δpre-CR: 269 ± 202 spikes/min vs. Δpost-CR: 232 ± 225 spikes/min; P = 0.54), and CR did not modify the recruitment of new AP clusters (Δpre-CR: -1 ± 3 vs. Δpost-CR: 0 ± 1; P = 0.39), or within-burst firing frequency (Δpre-CR: 3 ± 3 AP spikes/burst vs. Δpost-CR: 2 ± 2 AP spikes/burst; P = 0.21). These data indicate that CR improves some of the sympathetic nervous system dysregulation associated with cardiovascular disease, primarily via a reduction in resting sympathetic activation. However, the benefits of CR on sympathetic neural recruitment may depend upon the magnitude of initial impairment.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Mark B Badrov
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Division of Cardiology, Department of Medicine, University Health Network and Sinai Health System, University of Toronto, Toronto, Ontario, Canada
| | - Katelyn N Wood
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Schlegel-University of Waterloo Research Institute for Aging, Waterloo, Ontario, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Sophie Lalande
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Neville Suskin
- Cardiac Rehabilitation and Secondary Prevention Program of St. Joseph's Health Care London, London, Ontario, Canada.,Department of Medicine (Cardiology) and Program of Experimental Medicine, Western University, London, Ontario, Canada
| | - J Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
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2
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Sympathetic neural responses in heart failure during exercise and after exercise training. Clin Sci (Lond) 2021; 135:651-669. [DOI: 10.1042/cs20201306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 02/01/2021] [Accepted: 02/15/2021] [Indexed: 12/25/2022]
Abstract
Abstract
The sympathetic nervous system coordinates the cardiovascular response to exercise. This regulation is impaired in both experimental and human heart failure with reduced ejection fraction (HFrEF), resulting in a state of sympathoexcitation which limits exercise capacity and contributes to adverse outcome. Exercise training can moderate sympathetic excess at rest. Recording sympathetic nerve firing during exercise is more challenging. Hence, data acquired during exercise are scant and results vary according to exercise modality. In this review we will: (1) describe sympathetic activity during various exercise modes in both experimental and human HFrEF and consider factors which influence these responses; and (2) summarise the effect of exercise training on sympathetic outflow both at rest and during exercise in both animal models and human HFrEF. We will particularly highlight studies in humans which report direct measurements of efferent sympathetic nerve traffic using intraneural recordings. Future research is required to clarify the neural afferent mechanisms which contribute to efferent sympathetic activation during exercise in HFrEF, how this may be altered by exercise training, and the impact of such attenuation on cardiac and renal function.
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3
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Badrov MB, Wood KN, Lalande S, Sawicki CP, Borrell LJ, Barron CC, Vording JL, Fleischhauer A, Suskin N, McGowan CL, Shoemaker JK. Effects of 6 Months of Exercise-Based Cardiac Rehabilitation on Autonomic Function and Neuro-Cardiovascular Stress Reactivity in Coronary Artery Disease Patients. J Am Heart Assoc 2019; 8:e012257. [PMID: 31438760 PMCID: PMC6755845 DOI: 10.1161/jaha.119.012257] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/28/2019] [Indexed: 11/16/2022]
Abstract
Background Autonomic dysregulation represents a hallmark of coronary artery disease (CAD). Therefore, we investigated the effects of exercise-based cardiac rehabilitation (CR) on autonomic function and neuro-cardiovascular stress reactivity in CAD patients. Methods and Results Twenty-two CAD patients (4 women; 62±8 years) were studied before and following 6 months of aerobic- and resistance-training-based CR. Twenty-two similarly aged, healthy individuals (CTRL; 7 women; 62±11 years) served as controls. We measured blood pressure, muscle sympathetic nerve activity, heart rate, heart rate variability (linear and nonlinear), and cardiovagal (sequence method) and sympathetic (linear relationship between burst incidence and diastolic blood pressure) baroreflex sensitivity during supine rest. Furthermore, neuro-cardiovascular reactivity during short-duration static handgrip (20s) at 40% maximal effort was evaluated. Six months of CR lowered resting blood pressure (P<0.05), as well as muscle sympathetic nerve activity burst frequency (48±8 to 39±11 bursts/min; P<0.001) and burst incidence (81±7 to 66±17 bursts/100 heartbeats; P<0.001), to levels that matched CTRL and improved sympathetic baroreflex sensitivity in CAD patients (P<0.01). Heart rate variability (all P>0.05) and cardiovagal baroreflex sensitivity (P=0.11) were unchanged following CR, yet values were not different pre-CR from CTRL (all P>0.05). Furthermore, before CR, CAD patients displayed greater blood pressure and muscle sympathetic nerve activity reactivity to static handgrip versus CTRL (all P<0.05); yet, responses were reduced following CR (all P<0.05) to levels observed in CTRL. Conclusions Six months of exercise-based CR was associated with marked improvement in baseline autonomic function and neuro-cardiovascular stress reactivity in CAD patients, which may play a role in the reduced cardiac risk and improved survival observed in patients following exercise training.
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Affiliation(s)
- Mark B. Badrov
- School of KinesiologyWestern UniversityLondonOntarioCanada
| | | | - Sophie Lalande
- School of KinesiologyWestern UniversityLondonOntarioCanada
| | | | | | | | | | | | - Neville Suskin
- Cardiac Rehabilitation and Secondary Prevention Program of St. Joseph's Health Care LondonLondonOntarioCanada
- Department of Medicine (Cardiology) and Program of Experimental MedicineWestern UniversityLondonOntarioCanada
| | - Cheri L. McGowan
- School of KinesiologyWestern UniversityLondonOntarioCanada
- Department of KinesiologyUniversity of WindsorWindsorOntarioCanada
| | - J. Kevin Shoemaker
- School of KinesiologyWestern UniversityLondonOntarioCanada
- Department of Physiology and PharmacologyWestern UniversityLondonOntarioCanada
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4
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Notarius CF, Millar PJ, Keir DA, Murai H, Haruki N, O'Donnell E, Marzolini S, Oh P, Floras JS. Training heart failure patients with reduced ejection fraction attenuates muscle sympathetic nerve activation during mild dynamic exercise. Am J Physiol Regul Integr Comp Physiol 2019; 317:R503-R512. [PMID: 31365304 DOI: 10.1152/ajpregu.00104.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Muscle sympathetic nerve activity (MSNA) decreases during low-intensity dynamic one-leg exercise in healthy subjects but increases in patients with heart failure with reduced ejection fraction (HFrEF). We hypothesized that increased peak oxygen uptake (V̇o2peak) after aerobic training would be accompanied by less sympathoexcitation during both mild and moderate one-leg dynamic cycling, an attenuated muscle metaboreflex, and greater skin vasodilation. We studied 27 stable, treated HFrEF patients (6 women; mean age: 65 ± 2 SE yr; mean left ventricular ejection fraction: 30 ± 1%) and 18 healthy age-matched volunteers (6 women; mean age: 57 ± 2 yr). We assessed V̇o2peak (open-circuit spirometry) and the skin microcirculatory response to reactive hyperemia (laser flowmetry). Fibular MSNA (microneurography) was recorded before and during one-leg cycling (2 min unloaded and 2 min at 50% of V̇o2peak) and, to assess the muscle metaboreflex, during posthandgrip ischemia (PHGI). HFrEF patients were evaluated before and after 6 mo of exercise-based cardiac rehabilitation. Pretraining V̇o2peak and skin vasodilatation were lower (P < 0.001) and resting MSNA higher (P = 0.01) in HFrEF than control subjects. Training improved V̇o2peak (+3.0 ± 1.0 mL·kg-1·min-1; P < 0.001) and cutaneous vasodilation and diminished resting MSNA (-6.0 ± 2.0, P = 0.01) plus exercise MSNA during unloaded (-4.0 ± 2.5, P = 0.04) but not loaded cycling (-1.0 ± 4.0 bursts/min, P = 0.34) and MSNA during PHGI (P < 0.05). In HFrEF patients, exercise training lowers MSNA at rest, desensitizes the sympathoexcitatory metaboreflex, and diminishes MSNA elicited by mild but not moderate cycling. Training-induced downregulation of resting MSNA and attenuated reflex sympathetic excitation may improve exercise capacity and survival.
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Affiliation(s)
- Catherine F Notarius
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Philip J Millar
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.,Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Daniel A Keir
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Hisayoshi Murai
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Nobuhiko Haruki
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Emma O'Donnell
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.,School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Susan Marzolini
- Cardiovascular Prevention and Rehabilitation Program, Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
| | - Paul Oh
- Cardiovascular Prevention and Rehabilitation Program, Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
| | - John S Floras
- Division of Cardiology, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Koba S. Angiotensin II, Oxidative Stress, and Sympathetic Nervous System Hyperactivity in Heart Failure. Yonago Acta Med 2018. [PMID: 29946216 DOI: 10.33160/yam.2018.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In congestive heart failure (CHF), sympathetic nervous system is hyperactive. This article reviews current understandings about central and peripheral neural mechanisms underlying sympathetic hyperactivation in this pathological condition. During the development of CHF, renin-angiotensin system (RAS) activities and angiotensin II-mediated oxidative stress become enhanced. Here, on the basis of findings obtained from animal studies, it is examined how RAS overactivation and oxidative stress in central and peripheral nervous systems of CHF mediate sympathetic hyperactivation. Mechanisms by which exercise training in CHF ameliorates RAS overactivation, oxidative stress and sympathetic hyperactivation are also investigated.
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Affiliation(s)
- Satoshi Koba
- Division of Integrative Physiology, Department of Physiology, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan
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6
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Ferreira-Santos L, Martinez DG, Nicolau JC, Moreira HG, Alves MJ, Pereira AC, Trombetta IC, Negrão CE, Rondon MUPB. Neurovascular control during exercise in acute coronary syndrome patients with Gln27Glu polymorphism of β2-adrenergic receptor. PLoS One 2017; 12:e0173061. [PMID: 28235084 PMCID: PMC5325615 DOI: 10.1371/journal.pone.0173061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 02/14/2017] [Indexed: 12/02/2022] Open
Abstract
Background Gln27Glu (rs1042714) polymorphism of the β2-adrenergic receptor (ADRB2) has been association with cardiovascular functionality in healthy subjects. However, it is unknown whether the presence of the ADRB2 Gln27Glu polymorphism influences neurovascular responses during exercise in patients with acute coronary syndromes (ACS). We tested the hypothesis that patients with ACS homozygous for the Gln allele would have increased muscle sympathetic nerve activity (MSNA) responses and decreased forearm vascular conductance (FVC) responses during exercise compared with patients carrying the Glu allele (Gln27Glu and Glu27Glu). In addition, exercise training would restore these responses in Gln27Gln patients. Methods and results Thirty-days after an ischemic event, 61 patients with ACS without ventricular dysfunction were divided into 2 groups: (1) Gln27Gln (n = 35, 53±1years) and (2) Gln27Glu+Glu27Glu (n = 26, 52±2years). MSNA was directly measured using the microneurography technique, blood pressure (BP) was measured with an automatic oscillometric device, and blood flow was measured using venous occlusion plethysmography. MSNA, mean BP, and FVC were evaluated at rest and during a 3-min handgrip exercise. The MSNA (P = 0.02) and mean BP (P = 0.04) responses during exercise were higher in the Gln27Gln patients compared with that in the Gln27Glu+Glu27Glu patients. No differences were found in FVC. Two months of exercise training significantly decreased the MSNA levels at baseline (P = 0.001) and in their response during exercise (P = 0.02) in Gln27Gln patients, but caused no changes in Gln27Glu+Glu27Glu patients. Exercise training increased FVC responses in Gln27Glu+Glu27Glu patients (P = 0.03), but not in Gln27Gln patients. Conclusion The exaggerated MSNA and mean BP responses during exercise suggest an increased cardiovascular risk in patients with ACS and Gln27Gln polymorphism. Exercise training emerges as an important strategy for restoring this reflex control. Gln27Glu polymorphism of ADRB2 influences exercise-induced vascular adaptation in patients with ACS.
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Affiliation(s)
- Larissa Ferreira-Santos
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Daniel G. Martinez
- Faculty of Physical Education and Sports, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - José Carlos Nicolau
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
| | - Humberto G. Moreira
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
| | - Maria Janieire Alves
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
| | - Alexandre C. Pereira
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
| | | | - Carlos Eduardo Negrão
- Heart Institute (InCor-HCFMUSP), University of São Paulo Medical School, São Paulo, Brazil
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
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7
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Alves AJ, Viana JL, Cavalcante SL, Oliveira NL, Duarte JA, Mota J, Oliveira J, Ribeiro F. Physical activity in primary and secondary prevention of cardiovascular disease: Overview updated. World J Cardiol 2016; 8:575-583. [PMID: 27847558 PMCID: PMC5088363 DOI: 10.4330/wjc.v8.i10.575] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/14/2016] [Accepted: 08/18/2016] [Indexed: 02/06/2023] Open
Abstract
Although the observed progress in the cardiovascular disease treatment, the incidence of new and recurrent coronary artery disease remains elevated and constitutes the leading cause of death in the developed countries. Three-quarters of deaths due to cardiovascular diseases could be prevented with adequate changes in lifestyle, including increased daily physical activity. New evidence confirms that there is an inverse dose-response relationship between physical activity and cardiovascular disease and mortality risk. However, participation in moderate to vigorous physical activity may not fully attenuate the independent effect of sedentary activities on increased risk for cardiovascular diseases. Physical activity also plays an important role in secondary prevention of cardiovascular diseases by reducing the impact of the disease, slowing its progress and preventing recurrence. Nonetheless, most of eligible cardiovascular patients still do not benefit from secondary prevention/cardiac rehabilitation programs. The present review draws attention to the importance of physical activity in the primary and secondary prevention of cardiovascular diseases. It also addresses the mechanisms by which physical activity and regular exercise can improve cardiovascular health and reduce the burden of the disease.
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8
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Comparative effects of high intensity interval training versus moderate intensity continuous training on quality of life in patients with heart failure: Study protocol for a randomized controlled trial. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.ctrsc.2015.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Notarius CF, Millar PJ, Floras JS. Muscle sympathetic activity in resting and exercising humans with and without heart failure. Appl Physiol Nutr Metab 2015; 40:1107-15. [PMID: 26481289 DOI: 10.1139/apnm-2015-0289] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sympathetic nervous system is critical for coordinating the cardiovascular response to various types of physical exercise. In a number of disease states, including human heart failure with reduced ejection fraction (HFrEF), this regulation can be disturbed and adversely affect outcome. The purpose of this review is to describe sympathetic activity at rest and during exercise in both healthy humans and those with HFrEF and outline factors, which influence these responses. We focus predominately on studies that report direct measurements of efferent sympathetic nerve traffic to skeletal muscle (muscle sympathetic nerve activity; MSNA) using intraneural microneurographic recordings. Differences in MSNA discharge between subjects with and without HFrEF both at rest and during exercise and the influence of exercise training on the sympathetic response to exercise will be discussed. In contrast to healthy controls, MSNA increases during mild to moderate dynamic exercise in the presence of HFrEF. This increase may contribute to the exercise intolerance characteristic of HFrEF by limiting muscle blood flow and may be attenuated by exercise training. Future investigations are needed to clarify the neural afferent mechanisms that contribute to efferent sympathetic activation at rest and during exercise in HFrEF.
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Affiliation(s)
- Catherine F Notarius
- a University Health Network and Mount Sinai Hospital Division of Cardiology, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Philip J Millar
- b Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - John S Floras
- a University Health Network and Mount Sinai Hospital Division of Cardiology, University of Toronto, Toronto, ON M5G 2C4, Canada
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10
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Boyd AM. Regular exercise improves weight stability in patients with advanced heart failure. Ther Adv Cardiovasc Dis 2015; 9:297-304. [PMID: 25944851 DOI: 10.1177/1753944715581146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVES The purpose of this study was to determine if a progressive, prescribed home-based aerobic exercise program would alter the natural physiological processes that maintain fluid balance stability in patients with New York Heart Association (NYHA) class III/IV heart failure after medical optimization (titration of oral medical therapy with or without the infusion of an intravenous inotrope). METHODS A total of 56 men and women from a large tertiary trauma I hospital were enrolled with 56 subjects contributing to baseline analysis and 42 subjects at 24 weeks. Subjects were diagnosed with heart failure via NYHA classification IV or III for at least 6 months and were hospitalized for a current acute decompensation exacerbation in which they were being medically optimized. The exercise intervention was a home-based, prescribed, progressive aerobic exercise program lasting for 24 weeks. The exercise participants had weekly phone calls to gather data and progress the exercise program and one 12-week follow up. The usual care participants received random phone calls to collect data and had one 12-week follow up visit to attain physical assessment values. RESULTS Subjects were primarily female (59%), nonwhite (54%), and NYHA class IV (52%) versus class III (48%). The mean age was 58 years (±11.8 years). The subjects had a mean ejection fraction of 17.7 % (±7%) and mean maximal oxygen consumption of 12.1 (±3.4). Using a hierarchical multiple regression model, it was demonstrated that an exercise prescription (intensity, frequency, duration) significantly predicted 24 h weight fluctuations within a NYHA class III/IV heart failure population after medical optimization (R(2) linear = 0.713, F = 3.224, p = 0.015). CONCLUSION This study demonstrated that exercise is a successful adjunctive therapy to managing the daily weight variability or fluid status instability of patients with NYHA class III/IV heart failure that is often a debilitating aspect of the syndrome.
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Affiliation(s)
- Andrea M Boyd
- William J.B. Dorn VAMC, 6439 Garners Ferry Road, Columbia, SC 29209, USA
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11
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Negrao CE, Middlekauff HR, Gomes-Santos IL, Antunes-Correa LM. Effects of exercise training on neurovascular control and skeletal myopathy in systolic heart failure. Am J Physiol Heart Circ Physiol 2015; 308:H792-802. [PMID: 25681428 DOI: 10.1152/ajpheart.00830.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/09/2015] [Indexed: 12/14/2022]
Abstract
Neurohormonal excitation and dyspnea are the hallmarks of heart failure (HF) and have long been associated with poor prognosis in HF patients. Sympathetic nerve activity (SNA) and ventilatory equivalent of carbon dioxide (VE/VO2) are elevated in moderate HF patients and increased even further in severe HF patients. The increase in SNA in HF patients is present regardless of age, sex, and etiology of systolic dysfunction. Neurohormonal activation is the major mediator of the peripheral vasoconstriction characteristic of HF patients. In addition, reduction in peripheral blood flow increases muscle inflammation, oxidative stress, and protein degradation, which is the essence of the skeletal myopathy and exercise intolerance in HF. Here we discuss the beneficial effects of exercise training on resting SNA in patients with systolic HF and its central and peripheral mechanisms of control. Furthermore, we discuss the exercise-mediated improvement in peripheral vasoconstriction in patients with HF. We will also focus on the effects of exercise training on ventilatory responses. Finally, we review the effects of exercise training on features of the skeletal myopathy in HF. In summary, exercise training plays an important role in HF, working synergistically with pharmacological therapies to ameliorate these abnormalities in clinical practice.
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Affiliation(s)
- Carlos E Negrao
- Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil; School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil; and
| | - Holly R Middlekauff
- Departament of Medicine (Cardiology) and Physiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, California
| | - Igor L Gomes-Santos
- Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil
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12
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Edgell H, McMurtry MS, Haykowsky MJ, Paterson I, Ezekowitz JA, Dyck JRB, Stickland MK. Peripheral chemoreceptor control of cardiovascular function at rest and during exercise in heart failure patients. J Appl Physiol (1985) 2015; 118:839-48. [PMID: 25614600 DOI: 10.1152/japplphysiol.00898.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/20/2015] [Indexed: 01/01/2023] Open
Abstract
Peripheral chemoreceptor activity/sensitivity is enhanced in chronic heart failure (HF), and sensitivity is linked to greater mortality. This study aimed to determine the role of the peripheral chemoreceptor in cardiovascular control at rest and during exercise in HF patients and controls. Clinically stable HF patients (n = 11; ejection fraction: 39 ± 5%) and risk-matched controls (n = 10; ejection fraction: 65 ± 2%) performed randomized trials with or without dopamine infusion (2 μg·min(-1)·kg(-1)) at rest and during 40% maximal voluntary contraction handgrip (HG) exercise, and a resting trial of 2 min of inspired 100% oxygen. Both dopamine and hyperoxia were used to inhibit the peripheral chemoreceptor. At rest in HF patients, dopamine decreased ventilation (P = 0.02), decreased total peripheral resistance index (P = 0.003), and increased cardiac and stroke indexes (P ≤ 0.01), yet there was no effect of dopamine on these variables in controls (P ≥ 0.7). Hyperoxia lowered ventilation in HF (P = 0.01), but not in controls (P = 0.9), indicating suppression of the peripheral chemoreceptors in HF. However, no decrease of total peripheral resistance index was observed in HF. As expected, HG increased heart rate, ventilation, and brachial conductance of the nonexercising arm in controls and HF patients. During dopamine infusion, there were no changes in mean arterial pressure, heart rate, or ventilation responses to HG in either group (P ≥ 0.26); however, brachial conductance increased with dopamine in the control group (P = 0.004), but decreased in HF (P = 0.02). Our findings indicate that the peripheral chemoreceptor contributes to cardiovascular control at rest in HF patients and during exercise in risk-matched controls.
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Affiliation(s)
- Heather Edgell
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - M Sean McMurtry
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Mark J Haykowsky
- Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada; Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada; and
| | - Ian Paterson
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Justin A Ezekowitz
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Jason R B Dyck
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Michael K Stickland
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Cardiovascular and Stroke Research Centre (ABACUS), Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada; G.F. MacDonald Centre for Lung Health (Covenant Health), Edmonton, Alberta, Canada
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13
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Notarius CF, Millar PJ, Murai H, Morris BL, Marzolini S, Oh P, Floras JS. Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age-matched healthy subjects. J Physiol 2014; 593:715-22. [PMID: 25398528 DOI: 10.1113/jphysiol.2014.281873] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 11/03/2014] [Indexed: 01/12/2023] Open
Abstract
KEY POINTS People with diminished ventricular contraction who develop heart failure have higher sympathetic nerve firing rates at rest compared with healthy individuals of a similar age and this is associated with less exercise capacity. During handgrip exercise, sympathetic nerve activity to muscle is higher in patients with heart failure but the response to leg exercise is unknown because its recording requires stillness. We measured sympathetic activity from one leg while the other leg cycled at a moderate level and observed a decrease in nerve firing rate in healthy subjects but an increase in subjects with heart failure. Because these nerves release noradrenaline, which can restrict muscle blood flow, this observation helps explain the limited exercise capacity of patients with heart failure. Lower nerve traffic during exercise was associated with greater peak oxygen uptake, suggesting that if exercise training attenuated sympathetic outflow functional capacity in heart failure would improve. ABSTRACT The reflex fibular muscle sympathetic nerve (MSNA) response to dynamic handgrip exercise is elicited at a lower threshold in heart failure with reduced ejection fraction (HFrEF). The present aim was to test the hypothesis that the contralateral MSNA response to mild to moderate dynamic one-legged exercise is augmented in HFrEF relative to age- and sex-matched controls. Heart rate (HR), blood pressure and MSNA were recorded in 16 patients with HFrEF (left ventricular ejection fraction = 31 ± 2%; age 62 ± 3 years, mean ± SE) and 13 healthy control subjects (56 ± 2 years) before and during 2 min of upright one-legged unloaded cycling followed by 2 min at 50% of peak oxygen uptake (V̇O2,peak). Resting HR and blood pressure were similar between groups whereas MSNA burst frequency was higher (50.0 ± 2.0 vs. 42.3 ± 2.7 bursts min(-1), P = 0.03) and V̇O2,peak lower (18.0 ± 2.0 vs. 32.6 ± 2.8 ml kg(-1) min(-1), P < 0.001) in HFrEF. Exercise increased HR (P < 0.001) with no group difference (P = 0.1). MSNA burst frequency decreased during mild to moderate dynamic exercise in the healthy controls but increased in HFrEF (-5.5 ± 2.0 vs. 6.9 ± 1.8 bursts min(-1), P < 0.001). Exercise capacity correlated inversely with MSNA burst frequency at 50% V̇O2,peak (n = 29; r = -0.64; P < 0.001). At the same relative workload, one-legged dynamic exercise elicited a fall in MSNA burst frequency in healthy subjects but sympathoexcitation in HFrEF, a divergence probably reflecting between-group differences in reflexes engaged by cycling. This finding, coupled with an inverse relationship between MSNA burst frequency during loaded cycling and subjects' V̇O2,peak, is consistent with a neurogenic determinant of exercise capacity in HFrEF.
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Affiliation(s)
- Catherine F Notarius
- University Health Network and Mount Sinai Hospital Division of Cardiology, University of Toronto, Toronto, Ontario, Canada
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14
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Bouchard C, Antunes-Correa LM, Ashley EA, Franklin N, Hwang PM, Mattsson CM, Negrao CE, Phillips SA, Sarzynski MA, Wang PY, Wheeler MT. Personalized preventive medicine: genetics and the response to regular exercise in preventive interventions. Prog Cardiovasc Dis 2014; 57:337-46. [PMID: 25559061 DOI: 10.1016/j.pcad.2014.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Regular exercise and a physically active lifestyle have favorable effects on health. Several issues related to this theme are addressed in this report. A comment on the requirements of personalized exercise medicine and in-depth biological profiling along with the opportunities that they offer is presented. This is followed by a brief overview of the evidence for the contributions of genetic differences to the ability to benefit from regular exercise. Subsequently, studies showing that mutations in TP53 influence exercise capacity in mice and humans are succinctly described. The evidence for effects of exercise on endothelial function in health and disease also is covered. Finally, changes in cardiac and skeletal muscle in response to exercise and their implications for patients with cardiac disease are summarized. Innovative research strategies are needed to define the molecular mechanisms involved in adaptation to exercise and to translate them into useful clinical and public health applications.
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Affiliation(s)
- Claude Bouchard
- Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, USA.
| | | | - Euan A Ashley
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University, Stanford, CA, USA; Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA USA
| | - Nina Franklin
- Department of Physical Therapy, Department of Medicine, Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, IL, USA
| | - Paul M Hwang
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - C Mikael Mattsson
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University, Stanford, CA, USA; The Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Carlos E Negrao
- Heart Institute (InCor), Medical School, University of Sao Paulo, Sao Paulo, Brazil; School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil
| | - Shane A Phillips
- Department of Physical Therapy, Department of Medicine, Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, IL, USA
| | - Mark A Sarzynski
- Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Ping-Yuan Wang
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Matthew T Wheeler
- Center for Inherited Cardiovascular Disease, Division of Cardiovascular Medicine, Stanford University, Stanford, CA, USA; Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA USA
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15
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Koba S, Hisatome I, Watanabe T. Central command dysfunction in rats with heart failure is mediated by brain oxidative stress and normalized by exercise training. J Physiol 2014; 592:3917-31. [PMID: 24973409 DOI: 10.1113/jphysiol.2014.272377] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sympathoexcitation elicited by central command, a parallel activation of the motor and autonomic neural circuits in the brain, has been shown to become exaggerated in chronic heart failure (CHF). The present study tested the hypotheses that oxidative stress in the medulla in CHF plays a role in exaggerating central command-elicited sympathoexcitation, and that exercise training in CHF suppresses central command-elicited sympathoexcitation through its antioxidant effects in the medulla. In decerebrate rats, central command was activated by electrically stimulating the mesencephalic locomotor region (MLR) after neuromuscular blockade. The MLR stimulation at a current intensity greater than locomotion threshold in rats with CHF after myocardial infarction (MI) evoked larger (P < 0.05) increases in renal sympathetic nerve activity and arterial pressure than in sham-operated healthy rats (Sham) and rats with CHF that had completed longterm (8–12 weeks) exercise training (MI + TR). In the Sham and MI + TR rats, bilateral microinjection of a superoxide dismutase (SOD) mimetic Tempol into the rostral ventrolateral medulla (RVLM) had no effects on MLR stimulation-elicited responses. By contrast, in MI rats, Tempol treatment significantly reduced MLR stimulation-elicited responses. In a subset of MI rats, treatment with Tiron, another SOD mimetic, within the RVLM also reduced responses. Superoxide generation in the RVLM, as evaluated by dihydroethidium staining, was enhanced in MI rats compared with that in Sham and MI + TR rats. Collectively, these results support the study hypotheses. We suggest that oxidative stress in the medulla in CHF mediates central command dysfunction, and that exercise training in CHF is capable of normalizing central command dysfunction through its antioxidant effects in the medulla.
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Affiliation(s)
- Satoshi Koba
- Division of Integrative Physiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Ichiro Hisatome
- Division of Regenerative Medicine and Therapeutics, Graduate School of Medical Science, Tottori University, Yonago, Japan
| | - Tatsuo Watanabe
- Division of Integrative Physiology, Faculty of Medicine, Tottori University, Yonago, Japan
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Nunes RAB, Giampaoli V, de Freitas HFG, da Costa Pereira A, Araújo F, Correia GF, Rondon MUPB, Negrão CE, Mansur AJ. Exercise-Induced Muscle Vasodilatation and Treadmill Exercise Test Responses in Individuals without Overt Heart Disease. Cardiology 2014; 127:38-44. [DOI: 10.1159/000355157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022]
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