Gaël Deboeck 1 , Alain Van Muylem 2 , Jean Luc Vachiéry 2 , Robert Naeije 3 Show Affiliations »
Abstract
BACKGROUND: The distance walked in 6 minutes (6MWD) has been reported to be linearly related to peak oxygen uptake (VO2) in cardiac diseases and in lung diseases. In these patients, the VO2 during a 6-min walk test (walkVO2) has been found to be nearly equivalent to peakVO2, but with a lower respiratory exchange ratio (RER). Whether these observations translate to the less functionally impaired patients or healthy control subjects is not exactly known. METHODS: Thirty-two healthy control subjects and 15 chronic heart failure (CHF) patients performed a 6-min walk test and a maximal cardiopulmonary exercise test (CPET) both with measurements of gas exchange. RESULTS: The 6MWD and peakVO2 were linearly correlated, but with an increased slope appearing above 532 m. In CHF patients, walkVO2 was similar to peakVO2, but with lower heart rate and ventilation than measured at peak exercise. In healthy control subjects, VO2, ventilation and heart rate were lower during the 6-min walk than at maximal exercise but higher than at the anaerobic threshold. The RER during the 6-min walk remained <1 in both groups. CONCLUSIONS: Above 500 m, 6MWD becomes less sensitive to any increase in peakVO2. Furthermore, CHF patients and healthy control subjects exercise respectively at maximal and high VO2, but below the anaerobic threshold (as assessed by a CPET) during the 6-min walk test. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
BACKGROUND: The distance walked in 6 minutes (6MWD) has been reported to be linearly related to peak oxygen uptake (VO2) in cardiac diseases and in lung diseases . In these patients , the VO2 during a 6-min walk test (walkVO2) has been found to be nearly equivalent to peakVO2, but with a lower respiratory exchange ratio (RER). Whether these observations translate to the less functionally impaired patients or healthy control subjects is not exactly known. METHODS: Thirty-two healthy control subjects and 15 chronic heart failure (CHF ) patients performed a 6-min walk test and a maximal cardiopulmonary exercise test (CPET) both with measurements of gas exchange. RESULTS: The 6MWD and peakVO2 were linearly correlated, but with an increased slope appearing above 532 m. In CHF patients , walkVO2 was similar to peakVO2, but with lower heart rate and ventilation than measured at peak exercise. In healthy control subjects, VO2, ventilation and heart rate were lower during the 6-min walk than at maximal exercise but higher than at the anaerobic threshold. The RER during the 6-min walk remained <1 in both groups. CONCLUSIONS: Above 500 m, 6MWD becomes less sensitive to any increase in peakVO2. Furthermore, CHF patients and healthy control subjects exercise respectively at maximal and high VO2, but below the anaerobic threshold (as assessed by a CPET) during the 6-min walk test. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Entities: Chemical
Disease
Species
Keywords:
6-min walk test; chronic heart failure; exercise physiology; exercise testing; healthy subjects; oxygen consumption
Mesh： See more »
Year: 2013
PMID： 23513011 DOI： 10.1177/2047487313482283
Source DB: PubMed Journal: Eur J Prev Cardiol ISSN： 2047-4873 Impact factor: 7.804