Abstract: AIM: To investigate clinical significance of Six-Minute Walk Test (6MWT) and serum brain natriuretic peptide (BNP) levels in evaluating heart function in patients with chronic heart failure (CHF). METHODS: 51 patients with CHF (CHF group) and 30 healthy subjects served as control group were involved in the trials.The distance walked in six-minute and the serum levels of BNP-32 by enzyme-linked immunosorbent assay method were observed.The differences among 6MWT distance, BNP levels and different NYHA classes were analysed. RESULTS: The 6MWT distances in CHF group and control group were 380.3 ±121.7 and 546.8 ± 128.5 m, respectively (P <0.01).The serum levels of BNP in CHF group and control group were 758.3 ±289.5 and 109.3 ±37.6 ng·L^-1, respectively (P <0.01). The 6MWT distances in NYHA class Ⅱand Ⅲ of CHF patients were 425.0 ±105.8 and 335.6 ±126.1 m, respectively (P <0.01).The BNP levels in NYHA class Ⅱ and Ⅲ of CHF patients were 638.5 ±224.5 and 878.0±334.0 ng·L^-1, respectively (P <0.01).BNP levels in CHF patients of 6MWT distances among below 300, 300-374.9, 375-449.9 and above 450 m was 988.9 ±202.6, 768.6 ±217.4, 657.5 ±185.0 and 506.9 ±198.4 ng·L^-1, respectively (P <0.01).The 6MWT distance was inversely correlated to the BNP level (r=-0.752, P <0.01). CONCLUSION: Not only 6MWT distances but also serum BNP levels have an important clinical value in evaluating heart function of CHF.

Key words: heart failure, six-minute walk test, brain natriuretic peptide, diagnosis, heart function evaluation