Document Detail


Efficiency of neural drive during exercise in patients with COPD and healthy subjects.
MedLine Citation:
PMID:  20576733     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: It is unknown whether efficiency of neural drive as expressed by a ratio of ventilation to the diaphragm electromyogram (EMGdi) in patients with COPD differs from that of healthy subjects during exercise and whether maximal neural drive is exhibited at the point of exercise termination.
METHODS: We studied 12 male patients with COPD (mean ± SD age, 62.8 ± 10.3 years; FEV(1), 28.1 ± 10.2% predicted) and 12 age- and sex-matched healthy subjects (age, 61.1 ± 7.2 years, FEV(1), 101.5 ± 11.9% predicted). EMGdi was recorded from a multipair esophageal electrode during a constant work (80% of maximal oxygen consumption derived from a previous incremental exercise test) treadmill exercise. Minute ventilation and oxygen consumption were also measured.
RESULTS: Root mean square (RMS) of the EMGdi increased initially and reached a plateau at submaximal drive during constant load exercise in both patients with COPD and healthy subjects. The ratio of ventilation to EMGdi remained stable during exercise in healthy subjects from beginning to the end (100% ± 70% at the beginning and 100% ± 39% at the end, P > .05), whereas the ratio decreased gradually during exercise in patients with COPD (from 85% ± 66% to 42% ± 13%, P < .05).
CONCLUSIONS: Efficiency of neural drive decreases in patients with COPD during treadmill exercise. Neural respiratory drive reached a submaximal plateau during constant load exercise in both healthy subjects and patients with COPD, indicating that it may not be the only factor determining exercise capacity.
Authors:
Yin-Yin Qin; Joerg Steier; Caroline Jolley; John Moxham; Nan-Shan Zhong; Yuan-Ming Luo
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-06-24
Journal Detail:
Title:  Chest     Volume:  138     ISSN:  1931-3543     ISO Abbreviation:  Chest     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-12-08     Completed Date:  2011-01-13     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0231335     Medline TA:  Chest     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1309-15     Citation Subset:  AIM; IM    
Affiliation:
State Key Laboratory of Respiratory Disease, Guangzhou 510120, China. ym3698@yahoo.com.cn
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MeSH Terms
Descriptor/Qualifier:
Aged
Carbon Dioxide / metabolism
Case-Control Studies
Diaphragm / physiology*
Electrodes, Implanted
Electromyography / methods*
Exercise Test / methods*
Functional Residual Capacity
Humans
Male
Middle Aged
Oximetry
Oxygen Consumption / physiology
Pulmonary Disease, Chronic Obstructive / diagnosis*
Reference Values
Respiratory Function Tests
Respiratory System / physiopathology*
Severity of Illness Index
Total Lung Capacity
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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