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Amirav I, Manucot A, Crawley J, Levi S. Work of Breathing: Physiology, Measurement, and Diagnostic Value in Childhood Pneumonia. CHILDREN (BASEL, SWITZERLAND) 2024; 11:642. [PMID: 38929222 PMCID: PMC11202000 DOI: 10.3390/children11060642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
In clinical practice, increased "work of breathing" (WOB) is used to rapidly identify the acutely ill child in need of immediate clinical care, and is commonly used to support a clinical diagnosis of pneumonia. However, this key clinical sign is poorly understood and inconsistently defined. This review discusses the physiology, measurement, and clinical assessment of WOB, highlighting its utility in the recognition of pneumonia in under-resourced settings, where access to diagnostic imaging may be limited.
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Affiliation(s)
- Israel Amirav
- Pulmonary Unit, Dana-Dwek Children’s Hospital, Tel Aviv 6423906, Israel;
| | - Aleeza Manucot
- Department of Medicine, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Jane Crawley
- Centre for Tropical Medicine & Global Health, University of Oxford, Oxford OX3 7LG, UK;
| | - Sapir Levi
- Pulmonary Unit, Dana-Dwek Children’s Hospital, Tel Aviv 6423906, Israel;
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李 梦, 亢 玉, 寇 宇, 赵 双, 张 秀, 邱 丽, 颜 伟, 喻 鹏, 张 庆, 张 政. [Exploratory study on quantitative analysis of nocturnal breathing patterns in patients with acute heart failure based on wearable devices]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2023; 40:1108-1116. [PMID: 38151933 PMCID: PMC10753318 DOI: 10.7507/1001-5515.202310015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/29/2023] [Indexed: 12/29/2023]
Abstract
Patients with acute heart failure (AHF) often experience dyspnea, and monitoring and quantifying their breathing patterns can provide reference information for disease and prognosis assessment. In this study, 39 AHF patients and 24 healthy subjects were included. Nighttime chest-abdominal respiratory signals were collected using wearable devices, and the differences in nocturnal breathing patterns between the two groups were quantitatively analyzed. Compared with the healthy group, the AHF group showed a higher mean breathing rate (BR_mean) [(21.03 ± 3.84) beat/min vs. (15.95 ± 3.08) beat/min, P < 0.001], and larger R_RSBI_cv [70.96% (54.34%-104.28)% vs. 58.48% (45.34%-65.95)%, P = 0.005], greater AB_ratio_cv [(22.52 ± 7.14)% vs. (17.10 ± 6.83)%, P = 0.004], and smaller SampEn (0.67 ± 0.37 vs. 1.01 ± 0.29, P < 0.001). Additionally, the mean inspiratory time (TI_mean) and expiration time (TE_mean) were shorter, TI_cv and TE_cv were greater. Furthermore, the LBI_cv was greater, while SD1 and SD2 on the Poincare plot were larger in the AHF group, all of which showed statistically significant differences. Logistic regression calibration revealed that the TI_mean reduction was a risk factor for AHF. The BR_ mean demonstrated the strongest ability to distinguish between the two groups, with an area under the curve (AUC) of 0.846. Parameters such as breathing period, amplitude, coordination, and nonlinear parameters effectively quantify abnormal breathing patterns in AHF patients. Specifically, the reduction in TI_mean serves as a risk factor for AHF, while the BR_mean distinguishes between the two groups. These findings have the potential to provide new information for the assessment of AHF patients.
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Affiliation(s)
- 梦伟 李
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
- 四川大学华西医院 心脏内科(成都 610041)Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, P. R. China
| | - 玉 亢
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 宇晴 寇
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
- 四川大学华西医院 心脏内科(成都 610041)Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, P. R. China
| | - 双琳 赵
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 秀 张
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 丽叡 邱
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 伟 颜
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 鹏铭 喻
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 庆 张
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
| | - 政波 张
- 中国人民解放军医学院(北京 100853)Medical School of Chinese PLA, Beijing 100853, P. R. China
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Smith JR, Senefeld JW, Larson KF, Joyner MJ. Consequences of group III/IV afferent feedback and respiratory muscle work on exercise tolerance in heart failure with reduced ejection fraction. Exp Physiol 2023; 108:1351-1365. [PMID: 37735814 PMCID: PMC10900130 DOI: 10.1113/ep090755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 09/06/2023] [Indexed: 09/23/2023]
Abstract
Exercise intolerance and exertional dyspnoea are the cardinal symptoms of heart failure with reduced ejection fraction (HFrEF). In HFrEF, abnormal autonomic and cardiopulmonary responses arising from locomotor muscle group III/IV afferent feedback is one of the primary mechanisms contributing to exercise intolerance. HFrEF patients also have pulmonary system and respiratory muscle abnormalities that impair exercise tolerance. Thus, the primary impetus for this review was to describe the mechanistic consequences of locomotor muscle group III/IV afferent feedback and respiratory muscle work in HFrEF. To address this, we first discuss the abnormal autonomic and cardiopulmonary responses mediated by locomotor muscle afferent feedback in HFrEF. Next, we outline how respiratory muscle work impairs exercise tolerance in HFrEF through its effects on locomotor muscle O2 delivery. We then discuss the direct and indirect evidence supporting an interaction between locomotor muscle group III/IV afferent feedback and respiratory muscle work during exercise in HFrEF. Last, we outline future research directions related to locomotor and respiratory muscle abnormalities to progress the field forward in understanding the pathophysiology of exercise intolerance in HFrEF. NEW FINDINGS: What is the topic of this review? This review is focused on understanding the role that locomotor muscle group III/IV afferent feedback and respiratory muscle work play in the pathophysiology of exercise intolerance in patients with heart failure. What advances does it highlight? This review proposes that the concomitant effects of locomotor muscle afferent feedback and respiratory muscle work worsen exercise tolerance and exacerbate exertional dyspnoea in patients with heart failure.
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Affiliation(s)
- Joshua R. Smith
- Department of Cardiovascular MedicineMayo ClinicRochesterMNUSA
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative MedicineMayo ClinicRochesterMNUSA
- Department of Kinesiology and Community HealthUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | | | - Michael J. Joyner
- Department of Anesthesiology and Perioperative MedicineMayo ClinicRochesterMNUSA
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Cross TJ, Isautier JMJ, Kelley EF, Hubbard CD, Morris SJ, Smith JR, Duke JW. A Systematic Review of Methods Used to Determine the Work of Breathing during Exercise. Med Sci Sports Exerc 2023; 55:1672-1682. [PMID: 37126027 DOI: 10.1249/mss.0000000000003187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
INTRODUCTION Measurement of the work of breathing (Wb) during exercise provides useful insights into the energetics and mechanics of the respiratory muscles across a wide range of minute ventilations. The methods and analytical procedures used to calculate the Wb during exercise have yet to be critically appraised in the literature. PURPOSE The aim of this systematic review was to evaluate the quality of methods used to measure the Wb during exercise in the available literature. METHODS We conducted an extensive search of three databases for studies that measured the Wb during exercise in adult humans. Data were extracted on participant characteristics, flow/volume and pressure devices, esophageal pressure (P oes ) catheters, and methods of Wb analysis. RESULTS A total of 120 articles were included. Flow/volume sensors used were primarily pneumotachographs ( n = 85, 70.8%), whereas the most common pressure transducer was of the variable reluctance type ( n = 63, 52.5%). Esophageal pressure was frequently obtained via balloon-tipped catheters ( n = 114, 95.0%). Few studies mentioned calibration, frequency responses, and dynamic compensation of their measurement devices. The most popular method of measuring the Wb was pressure-volume integration ( n = 51, 42.5%), followed by the modified Campbell ( n = 28, 23.3%) and Dean & Visscher diagrams ( n = 26, 21.7%). Over one-third of studies did not report the methods used to process their pressure-volume data, and the majority (60.8%) of studies used the incorrect Wb units and/or failed to discuss the limitations of their Wb measurements. CONCLUSIONS The findings of this systematic review highlight the need for the development of a standardized approach for measuring Wb, which is informative, practical, and accessible for future researchers.
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Affiliation(s)
- Troy J Cross
- Faculty of Medicine and Health, University of Sydney, NSW, AUSTRALIA
| | | | - Eli F Kelley
- Air Force Research Laboratory, 711HPW/RHBFP, Wright-Patterson Air Force Base, OH
| | - Colin D Hubbard
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ
| | - Sarah J Morris
- Faculty of Medicine and Health, University of Sydney, NSW, AUSTRALIA
| | - Joshua R Smith
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ
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Villarraga N, Warner B, Bruhn EJ, Hammer SM, Bissen TG, Olson TP, Smith JR. Higher Work of Breathing During Exercise in Heart Failure With Preserved Ejection Fraction. Chest 2023; 163:1492-1505. [PMID: 36470415 PMCID: PMC10258442 DOI: 10.1016/j.chest.2022.11.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/21/2022] [Accepted: 11/21/2022] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND It is unknown if pulmonary alterations in heart failure with preserved ejection fraction (HFpEF) impact respiratory mechanics during exercise. RESEARCH QUESTION Are the operating lung volumes, work of breathing (Wb), and power of breathing (Pb) abnormal in patients with HFpEF during exercise? STUDY DESIGN AND METHODS Patients with HFpEF (n = 8; median age, 71 years [interquartile range (IQR), 66-80 years]) and control participants (n = 9; median age, 68 years [IQR, 64-74 years]) performed incremental cycling to volitional exhaustion. Esophageal pressure, end-expiratory lung volume (EELV), inspiratory lung volume (EILV), and ventilatory variables were compared at similar absolute (30 and 50 L/min) and relative (45% of peak, 70% of peak, and 100% of peak) minute ventilation (V.E) during exercise. RESULTS During exercise, EELVs were not different between patients with HFpEF and control participants (P > .13 for all). EILVs were lower in patients with HFpEF than control participants at 45% and 70% V.E peak (P < .03 for all). Dynamic lung compliance was lower in patients with HFpEF than control participants at 30 L/min, 50 L/min, 45% V.E peak, and 100% V.E peak (P < .04 for all). Compared with control participants, patients with HFpEF showed higher total Wb and Pb at 30 L/min (Wb: median, 1.08 J/L [IQR, 0.93-1.82 J/L] vs 0.52 J/L [IQR, 0.43-0.71 J/L]; Pb: median, 36 J/min [IQR, 30-59 J/min] vs 17 J/min [IQR, 11-23 J/min] and 50 L/min; Wb: median, 1.40 J/L [IQR, 1.27-1.68 J/L] vs 0.90 J/L [IQR, 0.74-1.05 J/L]; Pb: median, 73 J/min [IQR, 60-83 J/min] vs 45 J/min [IQR, 33-63 J/min]; P < .01 for all). At 30 and 50 L/min, inspiratory and expiratory resistive Wb and Pb were higher in patients with HFpEF than control participants (P < .04 for all). Total Wb was higher for patients with HFpEF than control participants at 45% of V.E peak (P = .02). Total Pb was higher for control participants than patients with HFpEF at 100% V.E peak because of higher inspiratory resistive Pb (P < .04 for both). INTERPRETATION These data demonstrate the HFpEF syndrome is associated with pulmonary alterations eliciting a greater Pb during exercise resulting from greater inspiratory and expiratory resistive Pb.
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Affiliation(s)
| | - Brit Warner
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Eric J Bruhn
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Shane M Hammer
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN; School of Kinesiology, Applied Health and Recreation, Oklahoma State University, Stillwater, OK
| | - Thomas G Bissen
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Thomas P Olson
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Joshua R Smith
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN.
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Butenas ALE, Copp SW, Hageman KS, Poole DC, Musch TI. Effects of comorbid type II diabetes mellitus and heart failure on rat hindlimb and respiratory muscle blood flow during treadmill exercise. J Appl Physiol (1985) 2023; 134:846-857. [PMID: 36825642 PMCID: PMC10042612 DOI: 10.1152/japplphysiol.00770.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/10/2023] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
In rats with type II diabetes mellitus (T2DM) compared with nondiabetic healthy controls, muscle blood flow (Q̇m) to primarily glycolytic hindlimb muscles and the diaphragm muscle are elevated during submaximal treadmill running consequent to lower skeletal muscle mass, a finding that held even when muscle mass was normalized to body mass. In rats with heart failure with reduced ejection fraction (HF-rEF) compared with healthy controls, hindlimb Q̇m was lower, whereas diaphragm Q̇m is elevated during submaximal treadmill running. Importantly, T2DM is the most common comorbidity present in patients with HF-rEF, but the effect of concurrent T2DM and HF-rEF on limb and respiratory Q̇m during exercise is unknown. We hypothesized that during treadmill running (20 m·min-1; 10% incline), hindlimb and diaphragm Q̇m would be higher in T2DM Goto-Kakizaki rats with HF-rEF (i.e., HF-rEF + T2DM) compared with nondiabetic Wistar rats with HF-rEF. Ejection fractions were not different between groups (HF-rEF: 30 ± 5; HF-rEF + T2DM: 28 ± 8%; P = 0.617), whereas blood glucose was higher in HF-rEF + T2DM (209 ± 150 mg/dL) compared with HF-rEF rats (113 ± 28 mg/dL; P = 0.040). Hindlimb muscle mass normalized to body mass was lower in rats with HF-rEF + T2DM (36.3 ± 1.6 mg/g) than in nondiabetic HF-rEF counterparts (40.3 ± 2.7 mg/g; P < 0.001). During exercise, Q̇m was elevated in rats with HF-rEF + T2DM compared with nondiabetic counterparts to the hindlimb (HF-rEF: 100 ± 28; HF-rEF + T2DM: 139 ± 23 mL·min-1·100 g-1; P < 0.001) and diaphragm (HF-rEF: 177 ± 66; HF-rEF + T2DM: 215 ± 93 mL·min-1·100g-1; P = 0.035). These data suggest that the pathophysiological consequences of T2DM on hindlimb and diaphragm Q̇m during treadmill running in the GK rat persist even in the presence of HF-rEF.NEW & NOTEWORTHY Herein, we demonstrate that rats comorbid with heart failure with reduced ejection fraction (HF-rEF) and type II diabetes mellitus (T2DM) have a higher hindlimb and respiratory muscle blood flow during submaximal treadmill running (20 m·min-1; 10% incline) compared with nondiabetic HF-rEF counterparts. These data may carry important clinical implications for roughly half of all patients with HF-rEF who present with T2DM.
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Affiliation(s)
- Alec L E Butenas
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - Steven W Copp
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - K Sue Hageman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
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Azimi G, Bozorgmehr R, Sattari P, Azimi A, Azimi H, Marzban-Rad S. Physiologic function of mediastinum space. Ann Med Surg (Lond) 2022; 82:104670. [PMID: 36268434 PMCID: PMC9577664 DOI: 10.1016/j.amsu.2022.104670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/09/2022] [Accepted: 09/10/2022] [Indexed: 11/20/2022] Open
Abstract
The mediastinum forms the central part of the thoracic cavity that is surrounded by pleural space on the two sides, thoracic vertebrae at the posterior, thoracic inlet on the top, and diaphragm at the bottom. It encompasses cardiopulmonary organs and organ systems. Pathological dysfunction or deformity in any part of the mediastinum can have adverse cardiovascular and respqiratory effects. Pectus excavatum and pectus carinatum are the most common congenital chest deformities that are characterized by sternal depression and protuberance of the sternum, respectively. Together, these account for 90% of chest wall deformities. Patients are known to be represented with respiratory distress and cardiovascular dysfunction. The aim of the review article is to present the anatomical and physiological role of the mediastinum in association with important parts of the thoracic cavity and pathological dysfunction of the mediastinum (cardiopulmonary system) due to pectus excavatum and pectus carinatum. Mediastinum forms the central part of thoracic cavity that is surrounded by pleural space. PC and PE are structural chest deformities. Chest deformation by pressing on the chin causes coughing, stridor, dyspnea and exacerbation. Clinical symptoms along with inflammation that requires urgent medical treatment.
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Affiliation(s)
- Ghasem Azimi
- Department of Internal Medicine, School of Medicine, Shahed University, Tehran, Iran
| | - Rama Bozorgmehr
- School of Medicine, Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Corresponding author. Pulmonary Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parastesh Sattari
- General Practitioner, Institute of Health Education and Research, Chamran Hospital, Tehran, Iran
| | - Ali Azimi
- Student of Research Committee, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Hossein Azimi
- Student of Research Committee, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Saeid Marzban-Rad
- Department of Surgery, Imam-Reza Hospital, Aja University of Tehran Medical Sciences, Tehran, Iran
- Corresponding author. Aja University of Tehran Medical Sciences, Tehran, Iran.
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Relationship between Driving Pressure and Mortality in Ventilated Patients with Heart Failure: A Cohort Study. Can Respir J 2021; 2021:5574963. [PMID: 34880958 PMCID: PMC8648448 DOI: 10.1155/2021/5574963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 10/09/2021] [Accepted: 11/17/2021] [Indexed: 11/17/2022] Open
Abstract
Background Heart failure (HF) is a leading cause of mortality and morbidity worldwide, with an increasing incidence. Invasive ventilation is considered to be essential for patients with HF. Previous studies have shown that driving pressure is associated with mortality in acute respiratory distress syndrome (ARDS). However, the relationship between driving pressure and mortality has not yet been examined in ventilated patients with HF. We assessed the association of driving pressure and mortality in patients with HF. Methods We conducted a retrospective cohort study of invasive ventilated adult patients with HF from the Medical Information Mart for Intensive Care-III database. We used multivariable logistic regression models, a generalized additive model, and a two-piecewise linear regression model to show the effect of the average driving pressure within 24 h of intensive care unit admission on in-hospital mortality. Results Six hundred and thirty-two invasive ventilated patients with HF were enrolled. Driving pressure was independently associated with in-hospital mortality (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.06–1.18; P < 0.001) after adjusted potential confounders. A nonlinear relationship was found between driving pressure and in-hospital mortality, which had a threshold around 14.27 cmH2O. The effect sizes and CIs below and above the threshold were 0.89 (0.75 to 1.05) and 1.17 (1.07 to 1.30), respectively. Conclusions There was a nonlinear relationship between driving pressure and mortality in patients with HF who were ventilated for more than 48 h, and this relationship was associated with increased in-hospital mortality when the driving pressure was more than 14.27 cmH2O.
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Cross TJ, Gideon EA, Morris SJ, Coriell CL, Hubbard CD, Duke JW. A comparison of methods used to quantify the work of breathing during exercise. J Appl Physiol (1985) 2021; 131:1123-1133. [PMID: 34410846 DOI: 10.1152/japplphysiol.00411.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanical work of breathing (Wb) is an insightful tool used to assess respiratory mechanics during exercise. There are several different methods used to calculate the Wb, however, each approach having its own distinct advantages/disadvantages. To date, a comprehensive assessment of the differences in the components of Wb between these methods is lacking. We therefore sought to compare the values of Wb during graded exercise as determined via the four most popular methods: 1) pressure-volume integration; 2) the Hedstrand diagram; 3) the Otis diagram; and the 4) modified Campbell diagram. Forty-two participants (30 ± 15 yr; 16 women) performed graded cycling to volitional exhaustion. Esophageal pressure-volume loops were obtained throughout exercise. These data were used to calculate the total Wb and, where possible, its subcomponents of inspiratory and expiratory, resistive and elastic Wb, using each of the four methods. Our results demonstrate that the components of Wb were indeed different between methods across the minute ventilations engendered by graded exercise. Importantly, however, no systematic pattern in these differences could be observed. Our findings indicate that the values of Wb obtained during exercise are uniquely determined by the specific method chosen to compute its value-no two methods yield identical results. Because there is currently no "gold-standard" for measuring the Wb, it is emphasized that future investigators be cognizant of the limitations incurred by their chosen method, such that observations made by others may be interpreted with greater context, and transparency.NEW & NOTEWORTHY The measurement of the work of breathing (Wb) during exercise provides us with deep insights into respiratory (patho)physiology, and sheds light on the putative factors which lead to respiratory muscle fatigue. There are 4 popular methods available to determine the Wb. Our study demonstrates that no two of these methods produce identical values of Wb during exercise. This paper also discusses the practical and theoretical limitations of each method.
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Affiliation(s)
- Troy J Cross
- Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Elizabeth A Gideon
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Sarah J Morris
- Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Catherine L Coriell
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Colin D Hubbard
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
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Smith JR, Berg JD, Curry TB, Joyner MJ, Olson TP. Respiratory muscle work influences locomotor convective and diffusive oxygen transport in human heart failure during exercise. Physiol Rep 2021; 8:e14484. [PMID: 32562374 PMCID: PMC7305241 DOI: 10.14814/phy2.14484] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 11/24/2022] Open
Abstract
Introduction It remains unclear if naturally occurring respiratory muscle (RM) work influences leg diffusive O2 transport during exercise in heart failure patients with reduced ejection fraction (HFrEF). In this retrospective study, we hypothesized that RM unloading during submaximal exercise will lead to increases in locomotor muscle O2 diffusion capacity (DMO2) contributing to the greater leg VO2. Methods Ten HFrEF patients and 10 healthy control matched participants performed two submaximal exercise bouts (i.e., with and without RM unloading). During exercise, leg blood flow was measured via constant infusion thermodilution. Intrathoracic pressure was measured via esophageal balloon. Radial arterial and femoral venous blood gases were measured and used to calculate leg arterial and venous content (CaO2 and CvO2, respectively), VO2, O2 delivery, and DMO2. Results From CTL to RM unloading, leg VO2, O2 delivery, and DMO2 were not different in healthy participants during submaximal exercise (all, p > .15). In HFrEF, leg VO2 (CTL: 0.7 ± 0.3 vs. RM unloading: 1.0 ± 0.4 L/min, p < .01), leg O2 delivery (CTL: 0.9 ± 0.4 vs. RM unloading: 1.4 ± 0.5 L/min, p < .01), and leg DMO2 (CTL: 31.5 ± 11.4 vs. RM unloading: 49.7 ± 18.6 ml min−1 mmHg−1) increased from CTL to RM unloading during submaximal exercise (all, p < .01), whereas CaO2‐CvO2 was not different (p = .51). The degree of RM unloading (i.e., % decrease in esophageal pressure‐time integral during inspiration) was related to the % increase in leg DMO2 with RM unloading (r = −.76, p = .01). Conclusion Our data suggest RM unloading leads to increased leg VO2 due to greater convective and diffusive O2 transport during submaximal exercise in HFrEF patients.
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Affiliation(s)
- Joshua R Smith
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jessica D Berg
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Timothy B Curry
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Michael J Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Thomas P Olson
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
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Smith JR, Hirai DM, Copp SW, Ferguson SK, Holdsworth CT, Hageman KS, Poole DC, Musch TI. Exercise training decreases intercostal and transversus abdominis muscle blood flows in heart failure rats during submaximal exercise. Respir Physiol Neurobiol 2021; 292:103710. [PMID: 34091075 DOI: 10.1016/j.resp.2021.103710] [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] [Received: 02/25/2021] [Revised: 05/18/2021] [Accepted: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Diaphragm muscle blood flow (BF) and vascular conductance (VC) are elevated with chronic heart failure (HF) during exercise. Exercise training (ExT) elicits beneficial respiratory muscle and pulmonary system adaptations in HF. We hypothesized that diaphragm BF and VC would be lower in HF rats following ExT than their sedentary counterparts (Sed). Respiratory muscle BFs and mean arterial pressure were measured via radiolabeled microspheres and carotid artery catheter, respectively, during submaximal treadmill exercise (20 m/min, 5 % grade). During exercise, no differences were present between HF + ExT and HF + Sed in diaphragm BFs (201 ± 36 vs. 227 ± 44 mL/min/100 g) or VCs (both, p > 0.05). HF + ExT compared to HF + Sed had lower intercostal BF (27 ± 3 vs. 41 ± 5 mL/min/100 g) and VC (0.21 ± 0.02 vs. 0.31 ± 0.04 mL/min/mmHg/100 g) during exercise (both, p < 0.05). Further, HF + ExT compared to HF + Sed had lower transversus abdominis BF (20 ± 1 vs. 35 ± 6 mL/min/100 g) and VC (0.14 ± 0.02 vs. 0.27 ± 0.05 mL/min/mmHg/100 g) during exercise (both, p < 0.05). These data suggest that exercise training lowers the intercostal and transversus abdominis BF responses in HF rats during submaximal treadmill exercise.
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Affiliation(s)
- Joshua R Smith
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, United States.
| | - Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States
| | - Steven W Copp
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States
| | - Scott K Ferguson
- Department of Kinesiology and Exercise Sciences, University of Hawaii, Hilo, HI, United States
| | - Clark T Holdsworth
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States
| | - K Sue Hageman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, KS, United States; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, United States
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12
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Kipp S, Leahy MG, Hanna JA, Sheel AW. Partitioning the work of breathing during running and cycling using optoelectronic plethysmography. J Appl Physiol (1985) 2021; 130:1460-1469. [PMID: 33703946 DOI: 10.1152/japplphysiol.00945.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Work of breathing ([Formula: see text]) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the respiratory musculature. It has long been known that abdominal activation increases with increasing exercise intensity, yet the mechanical work done by these muscles is not reflected in [Formula: see text]. Using optoelectronic plethysmography (OEP), we sought to show first that the volumes obtained from OEP (VCW) were comparable to volumes obtained from flow integration (Vt) during cycling and running, and second, to show that partitioned volume from OEP could be utilized to quantify the mechanical work done by the rib cage ([Formula: see text]RC) and abdomen ([Formula: see text]AB) during exercise. We fit 11 subjects (6 males/5 females) with reflective markers and balloon catheters. Subjects completed an incremental ramp cycling test to exhaustion and a series of submaximal running trials. We found good agreement between VCW versus Vt during cycling (bias = 0.002; P > 0.05) and running (bias = 0.016; P > 0.05). From rest to maximal exercise,[Formula: see text]AB increased by 84% (range: 30%-99%; [Formula: see text]AB: 1 ± 1 J/min to 61 ± 52 J/min). The relative contribution of the abdomen increased from 17 ± 9% at rest to 26 ± 16% during maximal exercise. Our study highlights and provides a quantitative measure of the role of the abdominal muscles during exercise. Incorporating the work done by the abdomen allows for a greater understanding of the mechanical tasks required by the respiratory muscles and could provide further insight into how the respiratory system functions during disease and injury.NEW & NOTEWORTHY We demonstrated that optoelectronic plethysmography (OEP) is a reliable tool to determine ventilatory volume changes during cycling and running, without restricting natural upper arm movements. Second, using OEP volumes coupled with pressure-derived measures, we calculated the work done by the rib cage and abdomen, respectively, during exercise. Collectively, our findings indicate that pulmonary mechanics can be accurately quantified using OEP, and abdominal work performed during ventilation contributes substantially to the overall work of the respiratory musculature.
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Affiliation(s)
- Shalaya Kipp
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael G Leahy
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jacob A Hanna
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - A William Sheel
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
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13
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Amaddeo A, Khraiche D, Khirani S, Meot M, Jais JP, Bonnet D, Fauroux B. Continuous positive airway pressure improves work of breathing in pediatric chronic heart failure. Sleep Med 2021; 83:99-105. [PMID: 33991896 DOI: 10.1016/j.sleep.2021.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/31/2021] [Accepted: 04/03/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Sleep disordered breathing (SDB) is common in adults with chronic heart failure (CHF), but its prevalence in children remains unclear. Continuous positive airway pressure (CPAP) is the treatment of SDB but deleterious hemodynamic effects have been reported. METHODS We prospectively analyzed SDB in children with CHF and the effect of CPAP on work of breathing (WOB) and cardiac index (CI). Children aged 6 months to 18 years old with CHF due to: 1) dilated cardiomyopathy (DM) with an ejection fraction < 45%, 2) functional single ventricle (SV) or 3) aortic or mitral valve disease awaiting surgery (VD) were eligible for the study. A polysomnography (PSG), measurement of WOB and CI during spontaneous breathing (SB) and CPAP (6, 8 and 10 cmH2O) were performed. RESULTS Thirty patients with mean age of 6.4 ± 5 years were included (16 DM 16, 10 SV, 4 LV). Twenty (73%) patients had a normal sleep efficiency. Median apnoeas hypopnea index (IAH) was within normal range at 1.6 events/h (0, 14) events/hour. Only one patient had central sleep apnoeas, none had Cheyne-Stokes respiration, and 3 patients had an obstructive AHI between 5 and 10 events/hour. Optimal CPAP level decreased WOB (p = 0.05) and respiratory rate (p = 0.01). CONCLUSIONS Severe SDB was uncommon in children with CHF. However, CPAP may be beneficial by decreasing WOB and respiratory rate without deleterious effects on CI.
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Affiliation(s)
- Alessandro Amaddeo
- Pediatric Noninvasive Ventilation and Sleep Unit, Hôpital Necker-Enfants Malades F-75015, Paris, France; Université de Paris, VIFASOM F-75004, Paris, France.
| | - Diala Khraiche
- Pediatric Cardiology, Centre de Référence des Malformations Cardiaques Congénitales Complexes-M3C, Hôpital Necker-Enfants Malades, Paris, France
| | - Sonia Khirani
- Pediatric Noninvasive Ventilation and Sleep Unit, Hôpital Necker-Enfants Malades F-75015, Paris, France
| | - Mathilde Meot
- Pediatric Cardiology, Centre de Référence des Malformations Cardiaques Congénitales Complexes-M3C, Hôpital Necker-Enfants Malades, Paris, France
| | - Jean-Philippe Jais
- INSERM U1163, Imagine Institute, Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Paris, France; AP-HP, Hôpital Necker Enfants Malades, Biostatistics Unit, Paris, France
| | - Damien Bonnet
- Pediatric Cardiology, Centre de Référence des Malformations Cardiaques Congénitales Complexes-M3C, Hôpital Necker-Enfants Malades, Paris, France; Université de Paris, Paris, France
| | - Brigitte Fauroux
- Pediatric Noninvasive Ventilation and Sleep Unit, Hôpital Necker-Enfants Malades F-75015, Paris, France; Université de Paris, VIFASOM F-75004, Paris, France
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14
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Gideon EA, Cross TJ, Coriell CL, Duke JW. The effect of estimating chest wall compliance on the work of breathing during exercise as determined via the modified Campbell diagram. Am J Physiol Regul Integr Comp Physiol 2021; 320:R268-R275. [PMID: 33356877 DOI: 10.1152/ajpregu.00263.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The modified Campbell diagram provides one of the most comprehensive assessments of the work of breathing (Wb) during exercise, wherein the resistive and elastic work of inspiration and expiration are quantified. Importantly, a necessary step in constructing the modified Campbell diagram is to obtain a value for chest wall compliance (CCW). To date, it remains unknown whether estimating or directly measuring CCW impacts the Wb, as determined by the modified Campbell diagram. Therefore, the purpose of this study was to evaluate whether the components of the Wb differ when the modified Campbell diagram is constructed using an estimated versus measured value of CCW. Forty-two participants (n = 26 men, 16 women) performed graded exercise to volitional exhaustion on a cycle ergometer. CCW was measured directly at rest via quasistatic relaxation. Estimated values of CCW were taken from prior literature. The measured value of CCW was greater than that obtained via estimation (214 ± 52 mL/cmH2O vs. 189 ± 18 mL/cmH2O; P < 0.05). At modest-to-high minute ventilations (i.e., 50-200 L/min), the inspiratory elastic Wb was greater and expiratory resistive Wb was lower, when modified Campbell diagrams were constructed using estimated compared with measured values of CCW (P = 0.001). These differences were however small and never exceeded ±5%. Thus, although our findings demonstrate that estimating CCW has a measurable impact on the determination of the Wb, its effect appears relatively small within a cohort of healthy adults during graded exercise.
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Affiliation(s)
- Elizbeth A Gideon
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Troy J Cross
- Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Catherine L Coriell
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
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15
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Hardy TA, Paula-Ribeiro M, Silva BM, Lyall GK, Birch KM, Ferguson C, Taylor BJ. The cardiovascular consequences of fatiguing expiratory muscle work in otherwise resting healthy humans. J Appl Physiol (1985) 2021; 130:421-434. [PMID: 33356985 DOI: 10.1152/japplphysiol.00116.2020] [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] Open
Abstract
In 11 healthy adults (25 ± 4 yr; 2 female, 9 male subjects), we investigated the effect of expiratory resistive loaded breathing [65% maximal expiratory mouth pressure (MEP), 15 breaths·min-1, duty cycle 0.5; ERLPm] on mean arterial pressure (MAP), leg vascular resistance (LVR), and leg blood flow ([Formula: see text]). On a separate day, a subset of five male subjects performed ERL targeting 65% of maximal expiratory gastric pressure (ERLPga). ERL-induced expiratory muscle fatigue was confirmed by a 17 ± 5% reduction in MEP (P < 0.05) and a 16 ± 12% reduction in the gastric twitch pressure response to magnetic nerve stimulation (P = 0.09) from before to after ERLPm and ERLPga, respectively. From rest to task failure in ERLPm and ERLPga, MAP increased (ERLPm = 31 ± 10 mmHg, ERLPga = 18 ± 9 mmHg, both P < 0.05), but group mean LVR and [Formula: see text] were unchanged (ERLPm: LVR = 0.78 ± 0.21 vs. 0.97 ± 0.36 mmHg·mL-1·min, [Formula: see text] = 133 ± 34 vs. 152 ± 74 mL·min-1; ERLPga: LVR = 0.70 ± 0.21 vs. 0.84 ± 0.33 mmHg·mL-1·min, [Formula: see text] = 160 ± 48 vs. 179 ± 110 mL·min-1) (all P ≥ 0.05). Interestingly, [Formula: see text] during ERLPga oscillated within each breath, increasing (∼66%) and decreasing (∼50%) relative to resting values during resisted expirations and unresisted inspirations, respectively. In conclusion, fatiguing expiratory muscle work did not affect group mean LVR or [Formula: see text] in otherwise resting humans. We speculate that any sympathetically mediated peripheral vasoconstriction was counteracted by transient mechanical effects of high intra-abdominal pressures during ERL.NEW & NOTEWORTHY Fatiguing expiratory muscle work in otherwise resting humans elicits an increase in sympathetic motor outflow; whether limb blood flow ([Formula: see text]) and leg vascular resistance (LVR) are affected remains unknown. We found that fatiguing expiratory resistive loaded breathing (ERL) did not affect group mean [Formula: see text] or LVR. However, within-breath oscillations in [Formula: see text] may reflect a sympathetically mediated vasoconstriction that was counteracted by transient increases in [Formula: see text] due to the mechanical effects of high intra-abdominal pressure during ERL.
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Affiliation(s)
- Tim A Hardy
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Marcelle Paula-Ribeiro
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.,Department of Physiology, Federal University of São Paulo, São Paulo, Brazil
| | - Bruno M Silva
- Department of Physiology, Federal University of São Paulo, São Paulo, Brazil
| | - Gemma K Lyall
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Karen M Birch
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Carrie Ferguson
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Bryan J Taylor
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.,Department of Cardiovascular Diseases, Mayo Clinic, Jacksonville, Florida
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16
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Yegorova S, Yegorov O, Ferreira LF. RNA-sequencing reveals transcriptional signature of pathological remodeling in the diaphragm of rats after myocardial infarction. Gene 2020; 770:145356. [PMID: 33333219 DOI: 10.1016/j.gene.2020.145356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/11/2020] [Accepted: 12/01/2020] [Indexed: 12/21/2022]
Abstract
The diaphragm is the main inspiratory muscle, and the chronic phase post-myocardial infarction (MI) is characterized by diaphragm morphological, contractile, and metabolic abnormalities. However, the mechanisms of diaphragm weakness are not fully understood. In the current study, we aimed to identify the transcriptome changes associated with diaphragm abnormalities in the chronic stage MI. We ligated the left coronary artery to cause MI in rats and performed RNA-sequencing (RNA-Seq) in diaphragm samples 16 weeks post-surgery. The sham group underwent thoracotomy and pericardiotomy but no artery ligation. We identified 112 differentially expressed genes (DEGs) out of a total of 9664 genes. Myocardial infarction upregulated and downregulated 42 and 70 genes, respectively. Analysis of DEGs in the framework of skeletal muscle-specific biological networks suggest remodeling in the neuromuscular junction, extracellular matrix, sarcomere, cytoskeleton, and changes in metabolism and iron homeostasis. Overall, the data are consistent with pathological remodeling of the diaphragm and reveal potential biological targets to prevent diaphragm weakness in the chronic stage MI.
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Affiliation(s)
- Svetlana Yegorova
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
| | - Oleg Yegorov
- Department of Neurosurgery, University of Florida, Gainesville, FL 32611, USA.
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
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17
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Evaluating the Benefits of Exercise Training in HFrEF or COPD Patients: ISO-LEVEL COMPARISON CAN ADD VALUABLE INFORMATION TO V˙o2peak. J Cardiopulm Rehabil Prev 2020; 40:421-426. [PMID: 33148990 DOI: 10.1097/hcr.0000000000000528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Heart failure with reduced ejection fraction (HFrEF) and chronic obstructive pulmonary disease (COPD) are relatively common conditions with similar symptoms of exercise intolerance and dyspnea. The aim of this study was to compare exercise capacity, ventilatory response, and breathing pattern in patient groups with either advanced HFrEF or COPD before and after exercise training. METHODS An observational study was conducted with parallel groups of 25 HFrEF and 25 COPD patients who took part in 6 wk of inpatient rehabilitation with exercise training. All patients underwent cardiopulmonary exercise tests at the start and end of the training, with resting arterial blood gas measurements. RESULTS The average peak oxygen uptake (V˙o2) was low at the start of the study but increased significantly after training in both groups, or by 2.2 ± 2.1 mL/kg/min in HFrEF patients and 1.2 ± 2.2 mL/kg/min in COPD patients. At ISO-V˙o2 (ie, same level of V˙o2 in pre- and post-exercise tests), carbon dioxide production (V˙co2) decreased after exercise training in both groups. Similarly, at ISO-V˙E (ie, same level of ventilation), breathing frequency (f) decreased and tidal volume (VT) increased, resulting in an improved breathing pattern (lower f/VT ratio) after training. CONCLUSION The findings of this study show that exercise training in severely affected patient groups with HFrEF or COPD led to an increase in maximal exercise capacity, a more favorable breathing pattern, and a diminished V˙co2 during exercise. Therefore, comparisons of V˙co2 and breathing pattern at ISO-levels of V˙o2 or V˙E before and after training are valuable and underutilized outcome measures in treatment studies.
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18
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Lalande S, Cross TJ, Keller-Ross ML, Morris NR, Johnson BD, Taylor BJ. Exercise Intolerance in Heart Failure: Central Role for the Pulmonary System. Exerc Sport Sci Rev 2020; 48:11-19. [PMID: 31453845 DOI: 10.1249/jes.0000000000000208] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We propose that abnormalities of the pulmonary system contribute significantly to the exertional dyspnea and exercise intolerance observed in patients with chronic heart failure. Interventions designed to address the deleterious pulmonary manifestations of heart failure may, therefore, yield promising improvements in exercise tolerance in this population.
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Affiliation(s)
- Sophie Lalande
- Department of Kinesiology and Heath Education, The University of Texas at Austin, Austin, TX
| | | | - Manda L Keller-Ross
- Divisions of Physical Therapy and Rehabilitation Sciences, Department of Rehabilitation Medicine, Medical School, University of Minnesota, Minneapolis, MN
| | - Norman R Morris
- School of Physiotherapy and Exercise Science, Griffith University, Queensland, Australia
| | - Bruce D Johnson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - Bryan J Taylor
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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19
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Cross TJ, Kim CH, Johnson BD, Lalande S. The interactions between respiratory and cardiovascular systems in systolic heart failure. J Appl Physiol (1985) 2019; 128:214-224. [PMID: 31774354 DOI: 10.1152/japplphysiol.00113.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heart failure (HF) is a complex and multifaceted disease. The disease affects multiple organ systems, including the respiratory system. This review provides three unique examples illustrating how the cardiovascular and respiratory systems interrelate because of the pathology of HF. Specifically, these examples outline the impact of HF pathophysiology on 1) respiratory mechanics and the mechanical "cost" of breathing; 2) mechanical interactions of the heart and lungs; and on 3) abnormalities of pulmonary gas exchange during exercise, and how this may be applied to treatment. The goal of this review is to, therefore, raise the awareness that HF, though primarily a disease of the heart, is accompanied by marked pathology of the respiratory system.
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Affiliation(s)
- Troy James Cross
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester Minnesota
| | - Chul-Ho Kim
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester Minnesota
| | - Bruce D Johnson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester Minnesota
| | - Sophie Lalande
- Department of Kinesiology and Heath Education, University of Texas at Austin, Austin, Texas
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20
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Effects of bi-level positive airway pressure on ventilatory and perceptual responses to exercise in comorbid heart failure-COPD. Respir Physiol Neurobiol 2019; 266:18-26. [PMID: 31005600 DOI: 10.1016/j.resp.2019.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/28/2019] [Accepted: 04/18/2019] [Indexed: 12/11/2022]
Abstract
This study tested the hypothesis that, by increasing the volume available for tidal expansion (inspiratory capacity, IC), bi-level positive airway pressure (BiPAP™) would lead to greater beneficial effects on dyspnea and exercise intolerance in comorbid heart failure (HF)-chronic obstructive pulmonary disease (COPD) than HF alone. Ten patients with HF and 9 with HF-COPD (ejection fraction = 30 ± 6% and 35 ± 7%; FEV1 = 83 ± 12% and 65 ± 15% predicted, respectively) performed a discontinuous exercise protocol under sham ventilation or BiPAP™. Time to intolerance increased with BiPAP™ only in HF-COPD (p < 0.05). BiPAP™ led to higher tidal volume and lower duty cycle with longer expiratory time (p < 0.05). Of note, BiPAP™ improved IC (by ∼0.5 l) across exercise intensities only in HF-COPD. These beneficial consequences were associated with lower dyspnea scores at higher levels of ventilation (p < 0.05). By improving the qualitative" (breathing pattern and operational lung volumes) and sensory (dyspnea) features of exertional ventilation, BiPAP™ might allow higher exercise intensities to be sustained for longer during cardiopulmonary rehabilitation in HF-COPD.
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21
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Dominelli PB, Katayama K, Vermeulen TD, Stuckless TJ, Brown CV, Foster GE, Sheel AW. Work of breathing influences muscle sympathetic nerve activity during semi-recumbent cycle exercise. Acta Physiol (Oxf) 2019; 225:e13212. [PMID: 30358142 DOI: 10.1111/apha.13212] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/17/2018] [Accepted: 10/18/2018] [Indexed: 02/06/2023]
Abstract
Reducing the work of breathing during exercise improves locomotor muscle blood flow and reduces diaphragm and locomotor muscle fatigue and is thought to be the result of a sympathetically mediated reflex. AIM The aim of this study was to assess muscle sympathetic nerve activity (MSNA) when the work of breathing is experimentally lowered during dynamic exercise. METHODS Healthy subjects (n = 12; age = 29 ± 9 years) performed semi-recumbent cycling trials at 40%, 60%, and 80% of peak workload. Exercise trials consisted of spontaneous breathing, reduced work of breathing (proportional assist ventilator), followed by further spontaneous breathing (post-ventilator). MSNA was recorded from the median nerve. RESULTS There was no difference in work of breathing between PAV and post-PAV at 40% peak work. At 60% peak work, the ventilator significantly (P < 0.05) reduced work of breathing (103 ± 39 vs 144 ± 47 J min-1 ), sympathetic nerve activity (35 ± 5 vs 42 ± 8 burst min-1 ), and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:math> (2.4 ± 0.5 vs 2.6 ± 0.5 L min-1 ) without influencing ventilation (86 ± 9 vs 82 ± 10 L min-1 ; P > 0.05), for PAV and post-PAV respectively. During 80% peak work (n = 8), the ventilator significantly (P < 0.05) reduced work of breathing (235 ± 110 vs. 361 ± 150 J min-1 ), MSNA (48 ± 7 vs 54 ± 11 burst min-1 ), and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:math> (2.9 ± 0.6 vs 3.2 ± 0.7 L min-1 ) but not ventilation (121 ± 20 vs 123 ± 20 L min-1 ; P > 0.05), for PAV and post-PAV respectively. There was a significant relationship between MSNA and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:math> (P < 0.0001) with a significant interaction due to the ventilator (P < 0.05). CONCLUSION Lowering the normally occurring work of breathing during exercise results in commensurate reductions in MSNA. Our findings provide evidence of a sympathetically mediated vasoconstrictor effect emanating from respiratory muscles during exercise.
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Affiliation(s)
- Paolo B. Dominelli
- School of Kinesiology University of British Columbia Vancouver British Columbia Canada
- Department of Anaesthesiology Mayo Clinic Rochester Minnesota
| | - Keisho Katayama
- Research Center of Health, Physical Fitness and Sports, Graduate School of Medicine Nagoya University Nagoya Japan
| | - Tyler D. Vermeulen
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences University of British Columbia Kelowna British Columbia Canada
| | - Troy J.R. Stuckless
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences University of British Columbia Kelowna British Columbia Canada
| | - Courtney V. Brown
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences University of British Columbia Kelowna British Columbia Canada
| | - Glen E. Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences University of British Columbia Kelowna British Columbia Canada
| | - Andrew William Sheel
- School of Kinesiology University of British Columbia Vancouver British Columbia Canada
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22
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Balmain BN, Jay O, Morris NR, Shiino K, Stewart GM, Jayasinghe R, Chan J, Sabapathy S. Thermoeffector Responses at a Fixed Rate of Heat Production in Heart Failure Patients. Med Sci Sports Exerc 2018; 50:417-426. [PMID: 29040221 DOI: 10.1249/mss.0000000000001455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Heart failure (HF) patients seem to exhibit altered thermoregulatory responses during exercise in the heat. However, the extent to which these responses are altered due to physiological impairments independently of biophysical factors associated with differences in metabolic heat production (Hprod), evaporative heat balance requirements (Ereq), and/or body size is presently unclear. Therefore, we examined thermoregulatory responses in 10 HF patients and 10 age-matched controls (CON) similar in body size during exercise at a fixed rate of Hprod and therefore Ereq in a 30°C environment. METHODS Rectal temperature, local sweat rate, and cutaneous vascular conductance were measured throughout 60 min of cycle ergometry. Whole-body sweat rate was estimated from pre-post nude body weight corrected for fluid intake. RESULTS Despite exercising at the same rate of Hprod (HF, 338 ± 43 W; CON, 323 ± 31 W; P = 0.25), the rise in rectal temperature was greater (P < 0.01) in HF (0.81°C ± 0.16°C) than in CON (0.49°C ± 0.27°C). In keeping with a similar Ereq (HF, 285 ± 40 W; CON, 274 ± 28 W; P = 0.35), no differences in whole-body sweat rate (HF, 0.45 ± 0.11 L·h; CON, 0.41 ± 0.07 L·h; P = 0.38) or local sweat rate (HF, 0.96 ± 0.17 mg·cm·min; CON, 0.79 ± 0.15 mg·cm·min; P = 0.50) were observed between groups. However, the rise in cutaneous vascular conductance was lower in HF than in CON (HF, 0.83 ± 0.42 au·mm Hg; CON, 2.10 ± 0.79 au·mm Hg; P < 0.01). In addition, the cumulative body heat storage estimated from partitional calorimetry was similar between groups (HF, 154 ± 106 kJ; CON, 196 ± 174 kJ; P = 0.44). CONCLUSIONS Collectively, these findings demonstrate that HF patients exhibit a blunted skin blood flow response, but no differences in sweating. Given that HF patients had similar body heat storage to that of CON at the same Hprod, their greater rise in core temperature can be attributed to a less uniform internal distribution of heat between the body core and periphery.
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Affiliation(s)
- Bryce N Balmain
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Ollie Jay
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Norman R Morris
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Kenji Shiino
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Glenn M Stewart
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Rohan Jayasinghe
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Jonathan Chan
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
| | - Surendran Sabapathy
- Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA.,Menzies Health Institute Queensland, Gold Coast, QLD, AUSTRALIA
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23
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Smith JR, Olson TP. Ventilatory constraints influence physiological dead space in heart failure. Exp Physiol 2018; 104:70-80. [PMID: 30298957 PMCID: PMC6312456 DOI: 10.1113/ep087183] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/08/2018] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The goal of this study was to investigate the effect of alterations in tidal volume and alveolar volume on the elevated physiological dead space and the contribution of ventilatory constraints thereof in heart failure patients during submaximal exercise. What is the main finding and its importance? We found that physiological dead space was elevated in heart failure via reduced tidal volume and alveolar volume. Furthermore, the degree of ventilatory constraints was associated with physiological dead space and alveolar volume. ABSTRACT Patients who have heart failure with reduced ejection fraction (HFrEF) exhibit impaired ventilatory efficiency [i.e. greater ventilatory equivalent for carbon dioxide ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:mi>C</mml:mi> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> ) slope] and elevated physiological dead space (VD /VT ). However, the impact of breathing strategy on VD /VT during submaximal exercise in HFrEF is unclear. The HFrEF (n = 9) and control (CTL, n = 9) participants performed constant-load cycling exercise at similar ventilation ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> </mml:math> ). Inspiratory capacity, operating lung volumes and arterial blood gases were measured during submaximal exercise. Arterial blood gases were used to derive VD /VT , alveolar volume, dead space volume, alveolar ventilation and dead space ventilation. During submaximal exercise, HFrEF patients had greater <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:mi>C</mml:mi> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> slope and VD /VT than CTL subjects (P = 0.01). At similar <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> </mml:math> , HFrEF patients had smaller tidal volumes and alveolar volumes (HFrEF 1.11 ± 0.33 litres versus CTL 1.66 ± 0.37 litres; both P ≤ 0.01), whereas dead space volume was not different (P = 0.47). The augmented breathing frequency in HFrEF patients resulted in greater dead space ventilation compared with CTL subjects (HFrEF 15 ± 4 l min-1 versus CTL 10 ± 5 l min-1 ; P = 0.048). The HFrEF patients exhibited greater increases in expiratory reserve volume and lower inspiratory capacity (as a percentage of predicted) than CTL subjects (both P < 0.05), which were significantly related to VD /VT and alveolar volume in HFrEF patients (all P < 0.03). In HFrEF, the reduced tidal volume and alveolar volume elevate physiological dead space during submaximal exercise, which is worsened in those with the greatest ventilatory constraints. These findings highlight the negative consequences of ventilatory constraints on physiological dead space during submaximal exercise in HFrEF.
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Affiliation(s)
- Joshua R Smith
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Thomas P Olson
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
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24
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Dominelli PB, Ripoll JG, Cross TJ, Baker SE, Wiggins CC, Welch BT, Joyner MJ. Sex differences in large conducting airway anatomy. J Appl Physiol (1985) 2018; 125:960-965. [PMID: 30024341 DOI: 10.1152/japplphysiol.00440.2018] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Airway luminal area is the major determinant of resistance to airflow in the tracheobronchial tree. Women may have smaller central conducting airways than men; however, previous evidence is confounded by an indirect assessment of airway geometry and by subjects with prior smoking history. The purpose of this study was to examine the effect of sex on airway size in healthy nonsmokers. Using low-dose high-resolution computed tomography, we retrospectively assessed airway luminal area in healthy men ( n = 51) and women ( n = 73) of varying ages (19-86 yr). Subjects with a positive smoking history, cardiopulmonary disease, or a body mass index > 40 kg/m2 were excluded. Luminal areas of the trachea, right and left main bronchus, bronchus intermediate, left and right upper lobes, and the left lower lobe were analyzed at three discrete points. The luminal areas of the conducting airways were ~26%-35% smaller in women. The trachea had the largest differences in luminal area between men and women (298 ± 47 vs. 195 ± 28 mm2 or 35% smaller for men and women, respectively), whereas the left lower lobe had the smallest differences (57 ± 15 vs. 42 ± 9 mm2 or 26% smaller for men and women, respectively). When a subset of subjects was matched for height, the sex differences in airway luminal area persisted, with women being ~20%-30% smaller. With all subjects, there were modest relationships between height and airway luminal area ( r = 0.73-0.53, P < 0.05). Although there was considerable overlap between sexes, the luminal areas of the large conducting airways were smaller in healthy women than in men. NEW & NOTEWORTHY Previous evidence for sex differences in airway size has been confounded by indirect measures and/or cohorts with significant smoking histories or pathologies. We found that central airways in healthy women were significantly smaller (~26%-35%) than men. The significant sex-difference in airway size was attenuated (20%-30% smaller) but preserved in a subset of subjects matched for height. Over a range of ages, healthy women have smaller central airways than men.
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Affiliation(s)
| | - Juan G Ripoll
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | - Troy J Cross
- Department of Cardiovascular Disease, Mayo Clinic, Rochester, Minnesota.,Menzies Health Institute Queensland, Griffith University, Brisbane, QLD, Australia
| | - Sarah E Baker
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | - Chad C Wiggins
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | - Brian T Welch
- Department of Radiology, Mayo Clinic, Rochester, Minnesota
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25
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Smith JR, Cross TJ, Van Iterson EH, Johnson BD, Olson TP. Resistive and elastic work of breathing in older and younger adults during exercise. J Appl Physiol (1985) 2018; 125:190-197. [PMID: 29672228 DOI: 10.1152/japplphysiol.01105.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is unknown whether the greater total work of breathing (WOB) with aging is due to greater elastic and/or resistive WOB. We hypothesized that older compared with younger adults would exhibit a greater total WOB at matched ventilations (V̇e) during graded exercise, secondary to greater inspiratory resistive and elastic as well as expiratory resistive WOB. Older (OA: 60 ± 8 yr; n = 9) and younger (YA: 38 ± 7 yr; n = 9) adults performed an incremental cycling test to volitional fatigue. Esophageal pressure, inspiratory (IRV) and expiratory reserve volumes (ERV), expiratory flow limitation (EFL), and ventilatory variables were measured at matched V̇e (i.e., 25, 50, and 75 l/min) during exercise. The inspiratory resistive and elastic as well as expiratory resistive WOB were quantified using the Otis method. At V̇e of 75 l/min, older adults had greater %EFL and larger tidal volumes to inspiratory capacity but smaller relative IRV ( P ≤ 0.03) than younger adults. Older compared with younger adults had greater total WOB at V̇E of 50 and 75 l/min (OA: 90 ± 43 vs. YA: 49 ± 21 J/min; P < 0.04 for both). At V̇e of 75 l/min, older adults had greater inspiratory elastic and resistive WOB (OA: 44 ± 27 vs. YA: 24 ± 22 and OA: 23 ± 15 vs. YA: 11 ± 3 J/min, respectively, P < 0.03 for both) and expiratory resistive WOB (OA: 23 ± 19 vs. YA: 14 ± 9 J/min, P = 0.02) than younger adults. These data demonstrate that aging-induced pulmonary alterations result in greater inspiratory elastic and resistive as well as expiratory resistive WOB, which may have implications for the integrated response during exercise. NEW & NOTEWORTHY Aging-induced changes to the pulmonary system result in increased work of breathing (WOB) during exercise. However, it is not known whether this higher WOB with aging is due to differences in elastic and/or resistive WOB. Herein, we demonstrate that older adults exhibited greater inspiratory elastic and resistive as well as expiratory resistive WOB during exercise.
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Affiliation(s)
- Joshua R Smith
- Department of Cardiovascular Medicine, Mayo Clinic , Rochester, Minnesota
| | - Troy J Cross
- Department of Cardiovascular Medicine, Mayo Clinic , Rochester, Minnesota
| | - Erik H Van Iterson
- Department of Cardiovascular Medicine, Mayo Clinic , Rochester, Minnesota
| | - Bruce D Johnson
- Department of Cardiovascular Medicine, Mayo Clinic , Rochester, Minnesota
| | - Thomas P Olson
- Department of Cardiovascular Medicine, Mayo Clinic , Rochester, Minnesota
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26
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Jorgenson CC, Chase SC, Olson LJ, Johnson BD. Assessment of Thoracic Blood Volume by Computerized Tomography in Patients With Heart Failure and Periodic Breathing. J Card Fail 2018; 24:479-483. [PMID: 29678727 DOI: 10.1016/j.cardfail.2018.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND Periodic breathing (PB) is often observed in patients with HF at rest, with sleep and during exercise. However, mechanisms underlying abnormal ventilatory control are not entirely established. METHODS Eleven subjects with HF (10 males, age = 69 ± 12 y) and 12 age-matched control subjects (8 males, age = 65 ± 9 y) participated in the study. PB was defined as a peak in the 0.003-0.04 Hz frequency range of the flow signal during 6 minutes of awake resting breathing. Thoracic blood volumes (Vt, thorax; Vh, heart; Vp, pulmonary), mean transit times (MTTs), and extravascular lung water (EVLW) were quantified using computerized tomography. RESULTS PB was observed in 7 subjects with HF and was associated with worse functional status. The HF PB-present group had thoracic blood volumes nearly double those of control and HF PB-absent subjects (volumes reported as mL/m2 body surface area, P values vs control: control = 813 ± 246, HF PB-absent = 822 ± 161 P = .981, HF PB-present = 1579 ± 548 P = .002). PB was associated with longer pulmonary MTT (control = 6.7 ± 1.2 s, HF PB-absent = 6.0 ± 0.8 s, HF PB-present = 8.4 ± 1.6 s; P = .033, HF PB-present vs HF PB-absent). EVLW was not elevated in the PB group. CONCLUSIONS Subjects with HF and PB at rest have greater centralization of blood volume.
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Affiliation(s)
| | - Steven C Chase
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Lyle J Olson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Bruce D Johnson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
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27
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Diaphragm abnormalities in heart failure and aging: mechanisms and integration of cardiovascular and respiratory pathophysiology. Heart Fail Rev 2018; 22:191-207. [PMID: 27000754 DOI: 10.1007/s10741-016-9549-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inspiratory function is essential for alveolar ventilation and expulsive behaviors that promote airway clearance (e.g., coughing and sneezing). Current evidence demonstrates that inspiratory dysfunction occurs during healthy aging and is accentuated by chronic heart failure (CHF). This inspiratory dysfunction contributes to key aspects of CHF and aging cardiovascular and pulmonary pathophysiology including: (1) impaired airway clearance and predisposition to pneumonia; (2) inability to sustain ventilation during physical activity; (3) shallow breathing pattern that limits alveolar ventilation and gas exchange; and (4) sympathetic activation that causes cardiac arrhythmias and tissue vasoconstriction. The diaphragm is the primary inspiratory muscle; hence, its neuromuscular integrity is a main determinant of the adequacy of inspiratory function. Mechanistic work within animal and cellular models has revealed specific factors that may be responsible for diaphragm neuromuscular abnormalities in CHF and aging. These include phrenic nerve and neuromuscular junction alterations as well as intrinsic myocyte abnormalities, such as changes in the quantity and quality of contractile proteins, accelerated fiber atrophy, and shifts in fiber type distribution. CHF, aging, or CHF in the presence of aging disturbs the dynamics of circulating factors (e.g., cytokines and angiotensin II) and cell signaling involving sphingolipids, reactive oxygen species, and proteolytic pathways, thus leading to the previously listed abnormalities. Exercise-based rehabilitation combined with pharmacological therapies targeting the pathways reviewed herein hold promise to treat diaphragm abnormalities and inspiratory muscle dysfunction in CHF and aging.
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28
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Cross TJ, Wheatley C, Stewart GM, Coffman K, Carlson A, Stepanek J, Morris NR, Johnson BD. The influence of thoracic gas compression and airflow density dependence on the assessment of pulmonary function at high altitude. Physiol Rep 2018; 6:e13576. [PMID: 29595881 PMCID: PMC5875542 DOI: 10.14814/phy2.13576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 12/14/2017] [Accepted: 12/17/2017] [Indexed: 11/27/2022] Open
Abstract
The purpose of this report was to illustrate how thoracic gas compression (TGC) artifact, and differences in air density, may together conflate the interpretation of changes in the forced expiratory flows (FEFs) at high altitude (>2400 m). Twenty-four adults (10 women; 44 ± 15 year) with normal baseline pulmonary function (>90% predicted) completed a 12-day sojourn at Mt. Kilimanjaro. Participants were assessed at Moshi (Day 0, 853 m) and at Barafu Camp (Day 9, 4837 m). Typical maximal expiratory flow-volume (MEFV) curves were obtained in accordance with ATS/ERS guidelines, and were either: (1) left unadjusted; (2) adjusted for TGC by constructing a "maximal perimeter" MEFV curve; or (3) adjusted for both TGC and differences in air density between altitudes. Forced vital capacity (FVC) was lower at Barafu compared with Moshi camp (5.19 ± 1.29 L vs. 5.40 ± 1.45 L, P < 0.05). Unadjusted data indicated no difference in the mid-expiratory flows (FEF25-75% ) between altitudes (∆ + 0.03 ± 0.53 L sec-1 ; ∆ + 1.2 ± 11.9%). Conversely, TGC-adjusted data revealed that FEF25-75% was significantly improved by sojourning at high altitude (∆ + 0.58 ± 0.78 L sec-1 ; ∆ + 12.9 ± 16.5%, P < 0.05). Finally, when data were adjusted for TGC and air density, FEFs were "less than expected" due to the lower air density at Barafu compared with Moshi camp (∆-0.54 ± 0.68 L sec-1 ; ∆-10.9 ± 13.0%, P < 0.05), indicating a mild obstructive defect had developed on ascent to high altitude. These findings clearly demonstrate the influence that TGC artifact, and differences in air density, bear on flow-volume data; consequently, it is imperative that future investigators adjust for, or at least acknowledge, these confounding factors when comparing FEFs between altitudes.
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Affiliation(s)
- Troy J. Cross
- Division of Cardiovascular DiseasesMayo ClinicRochesterMinnesota
- Menzies Health Institute QueenslandGriffith UniversitySouthportQueenslandAustralia
| | | | - Glenn M. Stewart
- Division of Cardiovascular DiseasesMayo ClinicRochesterMinnesota
- Menzies Health Institute QueenslandGriffith UniversitySouthportQueenslandAustralia
| | - Kirsten Coffman
- Division of Cardiovascular DiseasesMayo ClinicRochesterMinnesota
| | - Alex Carlson
- Division of Cardiovascular DiseasesMayo ClinicRochesterMinnesota
| | - Jan Stepanek
- Preventive, Occupational and Aerospace MedicineMayo ClinicScottsdaleArizona
| | - Norman R. Morris
- Menzies Health Institute QueenslandGriffith UniversitySouthportQueenslandAustralia
- Allied Health Research CollaborativeThe Prince Charles HospitalBrisbaneQueenslandAustralia
| | - Bruce D. Johnson
- Division of Cardiovascular DiseasesMayo ClinicRochesterMinnesota
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Smith JR, Ferguson SK, Hageman KS, Harms CA, Poole DC, Musch TI. Dietary nitrate supplementation opposes the elevated diaphragm blood flow in chronic heart failure during submaximal exercise. Respir Physiol Neurobiol 2017; 247:140-145. [PMID: 29037770 DOI: 10.1016/j.resp.2017.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/13/2017] [Accepted: 09/29/2017] [Indexed: 02/05/2023]
Abstract
Chronic heart failure (CHF) results in a greater cost of breathing and necessitates an elevated diaphragm blood flow (BF). Dietary nitrate (NO3‾) supplementation lowers the cost of exercise. We hypothesized that dietary NO3‾ supplementation would attenuate the CHF-induced greater cost of breathing and thus the heightened diaphragm BF during exercise. CHF rats received either 5days of NO3‾-rich beetroot (BR) juice (CHF+BR, n=10) or a placebo (CHF, n=10). Respiratory muscle BFs (radiolabeled microspheres) were measured at rest and during submaximal exercise (20m/min, 5% grade). Infarcted left ventricular area and normalized lung weight were not significantly different between groups. During submaximal exercise, diaphragm BF was markedly lower for CHF+BR than CHF (CHF+BR: 195±28; CHF: 309±71mL/min/100g, p=0.04). The change in diaphragm BF from rest to exercise was less (p=0.047) for CHF+BR than CHF. These findings demonstrate that dietary NO3‾ supplementation reduces the elevated diaphragm BF during exercise in CHF rats thus providing additional support for this therapeutic intervention in CHF.
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Affiliation(s)
- Joshua R Smith
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA.
| | - Scott K Ferguson
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - K Sue Hageman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Craig A Harms
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, KS 66506, USA; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, USA
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30
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Souza ASD, Sperandio PA, Mazzuco A, Alencar MC, Arbex FF, Oliveira MFD, O'Donnell DE, Neder JA. Influence of heart failure on resting lung volumes in patients with COPD. J Bras Pneumol 2017; 42:273-278. [PMID: 27832235 PMCID: PMC5063444 DOI: 10.1590/s1806-37562015000000290] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 05/09/2016] [Indexed: 01/04/2023] Open
Abstract
Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil.
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Affiliation(s)
- Aline Soares de Souza
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil.,Instituto Dante Pazzanese de Cardiologia, São Paulo (SP) Brasil
| | - Priscila Abreu Sperandio
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil.,Instituto Dante Pazzanese de Cardiologia, São Paulo (SP) Brasil
| | - Adriana Mazzuco
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil.,Departamento de Fisioterapia, Universidade Federal de São Carlos - UFSCAR - São Carlos (SP) Brasil
| | - Maria Clara Alencar
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil
| | - Flávio Ferlin Arbex
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil
| | - Mayron Faria de Oliveira
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil.,Instituto Dante Pazzanese de Cardiologia, São Paulo (SP) Brasil
| | - Denis Eunan O'Donnell
- Respiratory Investigation Unit, Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen's University, Kingston (ON) Canada
| | - José Alberto Neder
- Setor de Função Pulmonar e Fisiologia Clínica do Exercício - SEFICE - Disciplina de Pneumologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo - UNIFESP - São Paulo (SP) Brasil.,Laboratory of Clinical Exercise Physiology, Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen's University, Kingston (ON) Canada
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Smith JR, Hageman KS, Harms CA, Poole DC, Musch TI. Effect of chronic heart failure in older rats on respiratory muscle and hindlimb blood flow during submaximal exercise. Respir Physiol Neurobiol 2017; 243:20-26. [PMID: 28495570 DOI: 10.1016/j.resp.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 05/04/2017] [Accepted: 05/04/2017] [Indexed: 11/18/2022]
Abstract
Submaximal exercise diaphragm blood flow (BF) is elevated in young chronic heart failure (CHF) rats, while it is unknown if this occurs in older animals. Respiratory and hindlimb muscle BFs (radiolabeled microspheres) were measured at rest and during submaximal exercise (20m/min, 5% grade) in older healthy (n=7) and CHF (n=6) Fischer 344X Brown Norway rats (27-29 mo old). Older CHF, compared to healthy, rats had greater (p<0.01) left ventricular end-diastolic pressure and right ventricle and lung weight (normalized to body weight). During submaximal exercise, respiratory and hindlimb muscle BFs increased (p<0.02) in both groups, while diaphragm BF was higher (CHF: 257±32; healthy: 121±9mL/min/100g, p<0.01) and hindlimb BF lower (CHF: 111±10; healthy: 133±12mL/min/100g, p=0.04) in older CHF compared to healthy rats. Submaximal exercise hindlimb BF was negatively related (r=-0.93; p=0.03) to diaphragm BF in older CHF rats. During submaximal exercise, diaphragm BF is elevated in older CHF compared to healthy rats in proportion to the compromised hindlimb BF.
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Affiliation(s)
- Joshua R Smith
- Department of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA.
| | - K Sue Hageman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Craig A Harms
- Department of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, KS, 66506, USA; Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
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Caravita S, Vachiéry JL. Obstructive Ventilatory Disorder in Heart Failure-Caused by the Heart or the Lung? Curr Heart Fail Rep 2016; 13:310-318. [PMID: 27817003 DOI: 10.1007/s11897-016-0309-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Heart failure (HF) is a clinical syndrome frequently associated with airway obstruction, either as a respiratory comorbidity or as a direct consequence of HF pathophysiology. Recognizing the relative contribution of an underlying airway disease as opposed to airway obstruction due to volume overload and left atrial pressure elevation is of importance for the appropriate management of patients affected by HF. This review focuses on "les liaisons dangereuses" between the heart and the lungs, outlying recent advances linking in a vicious circle of chronic obstructive lung disease (COPD) and obstructive sleep apnea (OSA) on one side and HF on the other side. It also discusses the role of pivotal diagnostic tools such as pulmonary function tests and cardiopulmonary exercise test to determine the contribution of HF and COPD to symptoms and clinical status. Treatment implications are discussed as well.
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Affiliation(s)
- Sergio Caravita
- Department of Cardiovascular, Neural and Metabolic Sciences, S. Luca Hospital, Istituto Auxologico Italiano, IRCCS, Milan, Italy.,Pulmonary Hypertension and Heart Failure Clinic, Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Brussels, Belgium
| | - Jean-Luc Vachiéry
- Pulmonary Hypertension and Heart Failure Clinic, Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Brussels, Belgium. .,Department of Cardiology, CUB Hôpital Erasme, 808 Route de Lennik, 1070, Brussels, Belgium.
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Chase SC, Wheatley CM, Olson LJ, Beck KC, Wentz RJ, Snyder EM, Taylor BJ, Johnson BD. Impact of chronic systolic heart failure on lung structure-function relationships in large airways. Physiol Rep 2016; 4:4/13/e12867. [PMID: 27418546 PMCID: PMC4945845 DOI: 10.14814/phy2.12867] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 06/22/2016] [Indexed: 11/24/2022] Open
Abstract
Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF. Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty‐one HF (7F; age, 62 ± 11 years; ht. 175 ± 9 cm; wt. 91 ± 17 kg; LVEF, 28 ± 15%) and 29 controls (11F; age; 56 ± 11 years; ht. 174 ± 8 cm; wt. 77 ± 14 kg) completed the study. Subjects performed PFTs and a chest computed tomography (CT) scan before and after SABA. CT measures of attenuation, skew, and kurtosis were obtained from areas of lung tissue to assess EVLW. Airway luminal areas and wall thicknesses were also measured. CT tissue density suggested increased EVLW in HF without differences in the ratio of airway wall thickness to luminal area or luminal area to TLC (skew: 2.85 ± 1.08 vs. 2.11 ± 0.79, P < 0.01; Kurtosis: 15.5 ± 9.5 vs. 9.3 ± 5.5 P < 0.01; control vs. HF). PFTs were decreased in HF at baseline (% predicted FVC:101 ± 15% vs. 83 ± 18%, P < 0.01;FEV1:103 ± 15% vs. 82 ± 19%, P < 0.01;FEF25–75: 118 ± 36% vs. 86 ± 36%, P < 0.01; control vs. HF). Airway luminal areas, but not CT measures, were correlated with PFTs at baseline. The SABA cleared EVLW and decreased airway wall thickness but did not change luminal area. Patients with HF had evidence of increased EVLW, but not an expanded bronchial circulation. Airway caliber was maintained relative to controls, despite reductions in lung volume and flow rates. SABA improved lung function, primarily by reducing EVLW.
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Affiliation(s)
- Steven C Chase
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | | | - Lyle J Olson
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Kenneth C Beck
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Robert J Wentz
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Eric M Snyder
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Bryan J Taylor
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Bruce D Johnson
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
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Cross TJ, Beck KC, Johnson BD. Correcting the dynamic response of a commercial esophageal balloon-catheter. J Appl Physiol (1985) 2016; 121:503-11. [PMID: 27402558 DOI: 10.1152/japplphysiol.00155.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/03/2016] [Indexed: 11/22/2022] Open
Abstract
It is generally recommended that an esophageal balloon-catheter possess an adequate frequency response up to 15 Hz, such that parameters of respiratory mechanics may be quantified with precision. In our experience, however, we have observed that some commercially available systems do not display an ideal frequency response (<8-10 Hz). We therefore investigated whether the poor frequency response of a commercially available esophageal catheter may be adequately compensated using two numerical techniques: 1) an exponential model correction, and 2) Wiener deconvolution. These two numerical techniques were performed on a commercial balloon-catheter interfaced with 0, 1, and 2 lengths of extension tubing (90 cm each), referred to as configurations L0, L90, and L180, respectively. The frequency response of the balloon-catheter in these configurations was assessed by empirical transfer function analysis, and its "working" range was defined as the frequency beyond which more than 5% amplitude and/or phase distortion was observed. The working frequency range of the uncorrected balloon-catheter extended up to only 10 Hz for L0, and progressively worsened with additional tubing length (L90 = 3 Hz, L180 = 2 Hz). Although both numerical methods of correction adequately enhanced the working frequency range of the balloon-catheter to beyond 25 Hz for all length configurations (L0, L90, and L180), Wiener deconvolution consistently provided more accurate corrections. Our data indicate that Wiener deconvolution provides a superior correction of the balloon-catheter's dynamic response, and is relatively more robust to extensions in catheter tube length compared with the exponential correction method.
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Affiliation(s)
- Troy J Cross
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; and Menzie Health Institute Queensland, Griffith University, Brisbane, Queensland, Australia
| | - Kenneth C Beck
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; and
| | - Bruce D Johnson
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; and
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Fresiello L, Meyns B, Di Molfetta A, Ferrari G. A Model of the Cardiorespiratory Response to Aerobic Exercise in Healthy and Heart Failure Conditions. Front Physiol 2016; 7:189. [PMID: 27375488 PMCID: PMC4896934 DOI: 10.3389/fphys.2016.00189] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 05/10/2016] [Indexed: 11/13/2022] Open
Abstract
The physiological response to physical exercise is now recognized as an important tool which can aid the diagnosis and treatment of cardiovascular diseases. This is due to the fact that several mechanisms are needed to accommodate a higher cardiac output and a higher oxygen delivery to tissues. The aim of the present work is to provide a fully closed loop cardiorespiratory simulator reproducing the main physiological mechanisms which arise during aerobic exercise. The simulator also provides a representation of the impairments of these mechanisms in heart failure condition and their effect on limiting exercise capacity. The simulator consists of a cardiovascular model including the left and right heart, pulmonary and systemic circulations. This latter is split into exercising and non-exercising regions and is controlled by the baroreflex and metabolic mechanisms. In addition, the simulator includes a respiratory model reproducing the gas exchange in lungs and tissues, the ventilation control and the effects of its mechanics on the cardiovascular system. The simulator was tested and compared to the data in the literature at three different workloads whilst cycling (25, 49 and 73 watts). The results show that the simulator is able to reproduce the response to exercise in terms of: heart rate (from 67 to 134 bpm), cardiac output (from 5.3 to 10.2 l/min), leg blood flow (from 0.7 to 3.0 l/min), peripheral resistance (from 0.9 to 0.5 mmHg/(cm3/s)), central arteriovenous oxygen difference (from 4.5 to 10.8 ml/dl) and ventilation (6.1–25.5 l/min). The simulator was further adapted to reproduce the main impairments observed in heart failure condition, such as reduced sensitivity of baroreflex and metabolic controls, lower perfusion to the exercising regions (from 0.6 to 1.4 l/min) and hyperventilation (from 9.2 to 40.2 l/min). The simulator we developed is a useful tool for the description of the basic physiological mechanisms operating during exercise. It can reproduce how these mechanisms interact and how their impairments could limit exercise performance in heart failure condition. The simulator can thus be used in the future as a test bench for different therapeutic strategies aimed at improving exercise performance in cardiopathic subjects.
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Affiliation(s)
- Libera Fresiello
- Department of Clinical Cardiac Surgery, Katholieke Universiteit LeuvenLeuven, Belgium; Institute of Clinical Physiology, National Research CouncilRome, Italy
| | - Bart Meyns
- Department of Clinical Cardiac Surgery, Katholieke Universiteit Leuven Leuven, Belgium
| | - Arianna Di Molfetta
- Medical and Surgical Department of Pediatric Cardiology, Bambino Gesù Children's Hospital Rome, Italy
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Kee K, Stuart-Andrews C, Ellis MJ, Wrobel JP, Nilsen K, Sharma M, Thompson BR, Naughton MT. Increased Dead Space Ventilation Mediates Reduced Exercise Capacity in Systolic Heart Failure. Am J Respir Crit Care Med 2016; 193:1292-300. [DOI: 10.1164/rccm.201508-1555oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Arbex FF, Alencar MC, Souza A, Mazzuco A, Sperandio PA, Rocha A, Hirai DM, Mancuso F, Berton DC, Borghi-Silva A, Almeida DR, O'Donnell DE, Neder JA. Exercise Ventilation in COPD: Influence of Systolic Heart Failure. COPD 2016; 13:693-699. [DOI: 10.1080/15412555.2016.1174985] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Flavio F. Arbex
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Maria Clara Alencar
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Aline Souza
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Adriana Mazzuco
- Department of Physiotherapy, Federal University of Sao Carlos, Sao Carlos, Brazil
| | - Priscila A. Sperandio
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Alcides Rocha
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Daniel M. Hirai
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, Canada
| | - Frederico Mancuso
- Division of Cardiology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Danilo C. Berton
- Division of Respirology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Audrey Borghi-Silva
- Department of Physiotherapy, Federal University of Sao Carlos, Sao Carlos, Brazil
| | - Dirceu R. Almeida
- Division of Cardiology, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Denis E. O'Donnell
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, Canada
| | - J. Alberto Neder
- Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil
- Laboratory of Clinical Exercise Physiology and Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, Canada
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Laitano O, Ahn B, Patel N, Coblentz PD, Smuder AJ, Yoo JK, Christou DD, Adhihetty PJ, Ferreira LF. Pharmacological targeting of mitochondrial reactive oxygen species counteracts diaphragm weakness in chronic heart failure. J Appl Physiol (1985) 2016; 120:733-42. [PMID: 26846552 DOI: 10.1152/japplphysiol.00822.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/28/2016] [Indexed: 12/15/2022] Open
Abstract
Diaphragm muscle weakness in chronic heart failure (CHF) is caused by elevated oxidants and exacerbates breathing abnormalities, exercise intolerance, and dyspnea. However, the specific source of oxidants that cause diaphragm weakness is unknown. We examined whether mitochondrial reactive oxygen species (ROS) cause diaphragm weakness in CHF by testing the hypothesis that CHF animals treated with a mitochondria-targeted antioxidant have normal diaphragm function. Rats underwent CHF or sham surgery. Eight weeks after surgeries, we administered a mitochondrial-targeted antioxidant (MitoTEMPO; 1 mg·kg(-1)·day(-1)) or sterile saline (Vehicle). Left ventricular dysfunction (echocardiography) pre- and posttreatment and morphological abnormalities were consistent with the presence of CHF. CHF elicited a threefold (P < 0.05) increase in diaphragm mitochondrial H2O2 emission, decreased diaphragm glutathione content by 23%, and also depressed twitch and maximal tetanic force by ∼20% in Vehicle-treated animals compared with Sham (P < 0.05 for all comparisons). Diaphragm mitochondrial H2O2 emission, glutathione content, and twitch and maximal tetanic force were normal in CHF animals receiving MitoTEMPO. Neither CHF nor MitoTEMPO altered the diaphragm protein levels of antioxidant enzymes: superoxide dismutases (CuZn-SOD or MnSOD), glutathione peroxidase, and catalase. In both Vehicle and MitoTEMPO groups, CHF elicited a ∼30% increase in cytochrome c oxidase activity, whereas there were no changes in citrate synthase activity. Our data suggest that elevated mitochondrial H2O2 emission causes diaphragm weakness in CHF. Moreover, changes in protein levels of antioxidant enzymes or mitochondrial content do not seem to mediate the increase in mitochondria H2O2 emission in CHF and protective effects of MitoTEMPO.
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Affiliation(s)
- Orlando Laitano
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Bumsoo Ahn
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Nikhil Patel
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Philip D Coblentz
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Ashley J Smuder
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Jeung-Ki Yoo
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Demetra D Christou
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Peter J Adhihetty
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, Florida
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Abstract
Breathing exercises (BE) and inspiratory muscle training (IMT) have been demonstrated to improve ventilation and ventilation-to-perfusion matching, and to improve exercise, functional performance, and many pathophysiologic manifestations of heart failure (HF). This article provides an extensive review of BE and IMT in patients with HF and identifies several key areas in need of further investigation, including the role of expiratory muscle training, IMT targeted at various locations of inspiration (early, mid, or late inspiration), and alteration of the ratio of inspiratory time to total breath time, all of which have substantial potential to improve many pathophysiologic manifestations of HF.
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Affiliation(s)
- Lawrence P Cahalin
- Department of Physical Therapy, Leonard M. Miller School of Medicine, University of Miami, Miami, 5915 Ponce de Leon Boulevard, Coral Gables, FL 33146-2435, USA.
| | - Ross A Arena
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, 1919 West Taylor Street, Room 459, Chicago, IL 60612, USA
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Cross TJ, Lalande S, Hyatt RE, Johnson BD. Response characteristics of esophageal balloon catheters handmade using latex and nonlatex materials. Physiol Rep 2015; 3:3/6/e12426. [PMID: 26077619 PMCID: PMC4510628 DOI: 10.14814/phy2.12426] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The measurement of esophageal pressure allows for the calculation of several important and clinically useful parameters of respiratory mechanics. Esophageal pressure is often measured with balloon-tipped catheters. These catheters may be handmade from natural latex condoms and polyethylene tubing. Given the potential of natural latex to cause allergic reaction, it is important to determine whether esophageal catheter balloons can be fabricated, by hand, using nonlatex condoms as construction materials. To determine the static and dynamic response characteristics of esophageal balloon catheters handmade from latex and nonlatex materials, six esophageal catheter balloons were constructed from each of the following condom materials: natural latex, synthetic polyisoprene, and polyurethane (18 total). Static compliance and working volume range of each balloon catheter was obtained from their pressure-volume characteristics in water. The dynamic response of balloon catheters were measured via a pressure “step” test, from which a third-order underdamped transfer function was modeled. The dynamic ranges of balloon catheters were characterized by the frequencies corresponding to ±5% amplitude- and phase-distortion (fA5% and fφ5%). Balloon catheters handmade from polyurethane condoms displayed the smallest working volume range and lowest static balloon compliance. Despite this lower compliance, fA5% and fφ5% were remarkably similar between all balloon materials. Our findings suggest that polyisoprene condoms are an ideal nonlatex construction material to use when fabricating esophageal catheter balloons by hand.
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Affiliation(s)
- Troy J Cross
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
| | - Sophie Lalande
- Department of Kinesiology, University of Toledo, Toledo, Ohio
| | - Robert E Hyatt
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota
| | - Bruce D Johnson
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
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Iron supplementation effectively suppresses gastrocnemius muscle lesions to improve exercise capacity in chronic heart failure rats with anemia. Nutrition 2015; 31:1038-44. [PMID: 26059380 DOI: 10.1016/j.nut.2015.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 02/13/2015] [Accepted: 02/27/2015] [Indexed: 12/18/2022]
Abstract
OBJECTIVE For patients with chronic heart failure (CHF), exertional fatigue is one of the most common and debilitating symptoms. However, the poor relationship between heart dysfunction and exercise capacity has been ascribed to peripheral abnormalities. Several previous studies confirmed that iron supplementation could significantly improve the exercise capacity of patients with CHF, although they did not analyze effects in the musculoskeletal system. The aim of this study was to investigate the effect of iron treatment on gastrocnemius muscles of CHF rats with anemia. METHODS Male Sprague-Dawley rats were subjected to coronary ligation to induce heart failure. At the same time, blood (1-1.5 mL) was withdrawn from the retro-orbital plexus once every week to induce anemia. After 6 wk of this process, iron dextran was administered to the CHF rats with anemia (CHFa rats) at the dose of 8, 16, 32, or 64 mg/kg every 2 d for 2 wk. RESULTS Iron dextran (8 mg/kg every 2 d) effectively improved hemodynamic parameters (P < 0.05) compared with CHFa rats. Similarly, this dose of iron dextran significantly reduced the ratio of heart weight to body weight (P < 0.01), whereas it significantly increased the distance run (m) to exhaustion (P < 0.01). Iron dextran effectively inhibited sarcoplasmic vacuolation and muscle atrophy of gastrocnemius muscles in CHFa rats, as evaluated by pathologic examinations. Other iron treatments, however, were found to be ineffective on the same parameters, so particular focus was placed on the iron dextran (8 mg/kg every 2 d) group in subsequent analyses. Consistently, phospho-p38 in gastrocnemius muscles of CHFa rats was markedly suppressed by iron dextran. Additionally, iron dextran significantly decreased c-fos and c-jun and up-regulated cellular FLICE-inhibitory protein expression levels.
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42
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Mild training program in metabolic syndrome improves the efficiency of the oxygen pathway. Respir Physiol Neurobiol 2015; 208:8-14. [DOI: 10.1016/j.resp.2014.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/27/2014] [Accepted: 12/22/2014] [Indexed: 11/18/2022]
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Khirani S, Nathan N, Ramirez A, Aloui S, Delacourt C, Clément A, Fauroux B. Work of breathing in children with diffuse parenchymal lung disease. Respir Physiol Neurobiol 2015; 206:45-52. [DOI: 10.1016/j.resp.2014.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/06/2014] [Accepted: 11/24/2014] [Indexed: 12/26/2022]
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Taylor BJ, Olson TP, Chul-Ho-Kim, Maccarter D, Johnson BD. Use of noninvasive gas exchange to track pulmonary vascular responses to exercise in heart failure. CLINICAL MEDICINE INSIGHTS-CIRCULATORY RESPIRATORY AND PULMONARY MEDICINE 2013; 7:53-60. [PMID: 24093002 PMCID: PMC3785385 DOI: 10.4137/ccrpm.s12178] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We determined whether a non-invasive gas exchange based estimate of pulmonary vascular (PV) capacitance [PVCAP = stroke volume (SV) × pulmonary arterial pressure (Ppa)] (GXCAP) tracked the PV response to exercise in heart-failure (HF) patients. Pulmonary wedge pressure (Ppw), Ppa, PV resistance (PVR), and gas exchange were measured simultaneously during cycle exercise in 42 HF patients undergoing right-heart catheterization. During exercise, PETCO2 and VE/VCO2 were related to each other (r = −0.93, P < 0.01) and similarly related to mean Ppa (mPpa) (r = −0.39 and 0.36; P < 0.05); PETCO2 was subsequently used as a metric of mPpa. Oxygen pulse (O2 pulse) tracked the SV response to exercise (r = 0.91, P < 0.01). Thus, GXCAP was calculated as O2 pulse × PETCO2. During exercise, invasively determined PVCAP and non-invasive GXCAP were related (r = 0.86, P < 0.01), and GXCAP correlated with mPpa and PVR (r = −0.46 and −0.54; P < 0.01). In conclusion, noninvasive gas exchange measures may represent a simple way to track the PV response to exercise in HF.
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Affiliation(s)
- Bryan J Taylor
- Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
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Dynamic pulmonary hyperinflation occurs without expiratory flow limitation in chronic heart failure during exercise. Respir Physiol Neurobiol 2013; 189:34-41. [PMID: 23851110 DOI: 10.1016/j.resp.2013.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 06/19/2013] [Accepted: 06/19/2013] [Indexed: 11/23/2022]
Abstract
To assess the occurrence of tidal expiratory flow limitation (EFL) and/or dynamic pulmonary hyperinflation (DH) in chronic heart failure (CHF) during exercise 15 patients with stable systolic CHF, aged 69 ± 6yr, underwent pulmonary function testing and incremental cardio-pulmonary exercise testing. They subsequently performed constant load exercise testing at 30, 60 and 90% of respective maximum workload. At each step the presence of EFL, by negative expiratory pressure technique, and changes in inspiratory capacity (IC) were assessed. Ejection fraction amounted to 36 ± 6% and VO₂, peak (77 ± 19% pred.) was reduced. EFL was absent at any step during constant load exercise. In 6 patients IC decreased more than 10% pred. at highest step. Only in these patients TLC, FRC, RV FEF(25-75%) and DL(CO) were decreased at rest. VO₂, peak correlated with DL(CO), TLC and IC at rest and with IC (r(2)=0.59; p<0.001) and decrease in IC (r(2)=0.44; p<0.001) at 90% of maximum workload. During exercise CHF patients do not exhibit EFL, but some of them develop DH that is associated with lower VO₂, peak.
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CROSS TROYJ, BRESKOVIC TONI, SABAPATHY SURENDRAN, MASLOV PETRAZUBIN, JOHNSON BRUCED, DUJIC ZELJKO. Respiratory Muscle Pressure Development during Breath Holding in Apnea Divers. Med Sci Sports Exerc 2013; 45:93-101. [DOI: 10.1249/mss.0b013e3182690e6a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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