| Cardiorespiratory requirements of the 6-min walk test in older patients with left ventricular systolic dysfunction and no major structural heart disease. | |
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MedLine Citation:
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PMID: 17436192 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The six-minute walk test (6-MWT) is widely used to assess functional status in patients with chronic heart failure (CHF). The aims of the present study were: (1) to compare metabolic gas exchange during the 6-MWT in older patients with left ventricular systolic dysfunction (LVSD) and in breathless patients with no major structural heart disease (MSHD); (2) to determine the exercise intensity of the 6-MWT relative to peak oxygen uptake; (3) to establish the accuracy and reproducibility of the Metamax 3B ergospirometer during an incremental workload. Twenty four older patients with LVSD (19 male; age 76 +/- 5 years; BMI 27 +/- 4), and 18 patients with no MSHD (12 male; age 75 +/- 8 years; BMI 27 +/- 4) attended on consecutive days at the same time. Patients completed a 6-MWT with metabolic gas exchange measurements using the Metamax 3B portable ergospirometer, and an incremental cycle ergometry test using both the Metamax 3B and Oxycon Pro metabolic cart. Patients returned and performed a second 6-MWT and an incremental treadmill test, metabolic gas exchange was measured with the Metamax 3B. In patients with LVSD, the 6-MWT was performed at a higher fraction of maximal exercise capacity (p = 0.02). The 6-MWT was performed below the anaerobic threshold in patients with LVSD (83 %) and in patients with no MSHD (61 %). The Metamax 3B showed satisfactory to high accuracy at 10 W and 20 W in patients with LVSD (r = 0.77 - 0.97, p < 0.05), and no MSHD (r = 0.76 - 0.94, p < 0.05). Metabolic gas exchange variables measured during the 6-MWT showed satisfactory to high day-to-day reproducibility in patients with LVSD (ICC = 0.75 - 0.98), but a higher variability was evident in participants with no MSHD (ICC = 0.62 - 0.97). The Metamax 3B portable ergospirometer is an accurate and reproducible device during submaximal, fixed rate exercise in older patients with LVSD and no MSHD. In elderly patients with LVSD and no MSHD, the 6-MWT should not be considered a maximal test of exercise capacity but rather a test of submaximal exercise performance. Our study demonstrates that the 6-MWT takes place at a higher proportion of peak oxygen uptake in patients with LVSD compared to those with no MSHD, and may be one reason why fatigue is a more prominent symptom in these patients. |
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Authors:
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L Ingle; M Wilkinson; S Carroll; C Boyes; R Butterly; R King; C Cooke; J Cleland; A Clark |
Publication Detail:
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Type: Journal Article Date: 2007-04-13 |
Journal Detail:
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Title: International journal of sports medicine Volume: 28 ISSN: 0172-4622 ISO Abbreviation: Int J Sports Med Publication Date: 2007 Aug |
Date Detail:
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Created Date: 2007-07-31 Completed Date: 2007-10-25 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8008349 Medline TA: Int J Sports Med Country: Germany |
Other Details:
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Languages: eng Pagination: 678-84 Citation Subset: IM |
Affiliation:
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Carnegie Research Institute, Leeds Metropolitan University, Beckett's Park Campus, Leeds, United Kingdom. L.Ingle@leedsmet.ac.uk |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Aged Aged, 80 and over Exercise Test Great Britain Heart Failure Humans Male Oxygen Consumption / physiology Pulmonary Gas Exchange / physiology* Ventricular Dysfunction, Left / physiopathology* Walking / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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