Assessment of exercise capacity in African patients with chronic heart failure using six minutes walk test

The purpose of this study was to assess the functional capacity during a 6-minute corridor walk and a 6-minute bicycle ergometry exercise in patients with chronic heart failure (CHF).

Thirty five patients with stable CHF were recruited for the study. Each subject performed six minutes corridor walk and 6-minute bicycle ergometry testing. The 6-minute walk required the subjects to walk at a self selected speed on a 20 meter marked level ground for 6-minute. All the subjects also performed a 6-minute exercise on a stationary bicycle ergometer with initial resistance of 20 watts and increased by 10 watts after 3-minutes. The perceived rate of exertion was assessed using a modified Borg Scale after each exercise mode. The maximum oxygen consumption was derived using American College of Sport Medicine equations.

Result showed high positive correlation between distance walked in the 6-minute and the maximum volume of oxygen (VO(2) max) (r = 0.65, P < 0.01). The average distance walked was 327 m +/- 12.03 m. The VO(2) max estimated during bicycle ergometry was higher (13.7 +/- 1.9 L) than during the six minutes walk (8.9 +/- 1.2 L).

Six minutes walk could be useful to evaluate exercise tolerance in patients with chronic heart failure, while the bicycle ergometer could be more appropriate in the assessment of maximum functional capacity in these patients.