INCREASED WALKING VARIABILITY IN ELDERLY PERSONS WITH CONGESTIVE-HEART-FAILURE

OBJECTIVES: To determine the effects of congestive heart failure on a person's ability to walk at a steady pace while ambulating at a self-d etermined rate. SETTING: Beth Israel Hospital, Boston, a primary and t ertiary teaching hospital, and a social activity center for elderly ad ults living in the community. PARTICIPANTS: Eleven elderly subjects (a ged 70-93 years) with well compensated congestive heart failure (NY He art Association class I or II), seven elderly subjects (aged 70-79 yea rs) without congestive heart failure, and 10 healthy young adult subje cts (aged 20-30 years). MEASUREMENTS: Subjects walked for 8 minutes on level ground at their own selected walking rate. Footswitches were us ed to measure the time between steps. Step rate (steps/minute) and ste p rate variability were calculated for the entire walking period, for 30 seconds during the first minute of the walk, for 30 seconds during the last minute of the walk, and for the 30-second period when each su bject's step rate variability was minimal. Group means and 5% and 95% confidence intervals were computed. MAIN RESULTS: All measures of walk ing variability were significantly increased in the elderly subjects w ith congestive heart failure, intermediate in the elderly controls, an d lowest in the young subjects. There was no overlap between the three groups using the minimal 30-second variability (elderly CHF vs elderl y controls: P < 0.001, elderly controls vs young: P < 0.001), and no o verlap between elderly subjects with and without congestive heart fail ure when using the overall variability. For all four measures, there w as no overlap in any of the confidence intervals, and all group means were significantly different (P < 0.05). CONCLUSIONS : Step rate varia bility is increased in elderly subjects with well compensated congesti ve heart failure compared with elderly subjects without congestive hea rt failure and healthy young adults.