A comparison of the 6-minute walk test and symptom limited graded exercise test for phase II cardiac rehabilitation of older adults

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldBackground and Purpose: Older adults often find it difficult to bicycle or walk on a treadmill. Therefore we prospectively evaluated whether the 6-minute walk test (6MWT) could be used as a valid substitute for symptom limited graded exercise testing (SLGXT) to determine exercise capacity in a group of cardiovascularly stable older adults after cardiac surgery. Subjects: Ten older adults who had undergone cardiac surgery participated in the study. Methods: The pedaling speed of the SLGXT was 55-60 rpm, beginning at 20 watts and increasing incrementally until exhaustion. Perceived exertion was rated using the Borg rating scale. Four 6MWTs were performed during the same day with a rest periods of 15-60 minutes. The best distance achieved in the four 6MWTs was used in subsequent analysis. Descriptive statistics and Pearson’s correlation coefficients were calculated. Results: Performance at the 6MWT and the SLGXT were highly and significantly correlated (r = .93, p< .001). The maximum heart rate achieved during the best 6MWT and the SLGXT were moderately and significantly correlated (r = .64, p< .009). The correlation between maximum systolic blood pressure during the 6MWT and SLGXT was somewhat lower (r = .52, p< .038). Conclusions: The 6MWT can be used as a valid substitute for ‘the golden standard’ SLGXT to evaluate exercise capacity after phase II rehabilitation of cardiovascularly stable older adults who have undergone cardiac surgery