Six minute walking test for assessing exercise capacity in chronic heart failure.

Twenty six patients, mean age 58 years (range 36-68), with stable chronic heart failure, New York Heart Association class II-III, and 10 normal subjects of a similar age range were studied. Exercise capacity was assessed by determining oxygen consumption reached during a maximal treadmill exercise test and by measuring the distance each patient walked in six minutes. There were significant differences in the distance walked in six minutes between normal subjects, patients with heart failure, class II, and those with class III heart failure (683 m, 558 m, and 402 m, respectively (p less than 0.003)). The relation between maximal oxygen consumption and the distance walked in six minutes was curvilinear; thus the distance walked varied considerably in those with a low maximal oxygen consumption but varied little in patients and normal subjects with a high maximal oxygen consumption. All subjects preferred performing the six minute walking test to the treadmill exercise test, considering it to be more closely related to their daily physical activity. The six minute test is a simple objective guide to disability in patients with chronic heart failure and could be of particular value in assessing patients with severe heart failure but less useful in assessing patients with mild heart failure.