|| Checking for direct PDF access through Ovid
Background: The 6-min walk test (6-MWT) may serve as a simple clinical tool to assess functional capacity in patients with heart failure. The aim of this study was to prospectively examine whether a 6-MWT result correlates with cardiac function measurements in patients with heart failure.Methods: In 231 patients (mean age 61.6±10 years, 51.5% male) with signs of congestive heart failure (NYHA: 2.25±0.7), a 6-MWT and an echo-Doppler study were performed in the same day. Left ventricular (LV) end-diastolic (EDD) and end-systolic (ESD) dimensions, fractional shortening (FS), ejection fraction (EF) and E:A ratio, were measured. Restrictive filling was defined as E:A ratio >1.5 and E-wave deceleration <140ms. LV long axis function was studied using M-mode (amplitude) and tissue Doppler (myocardial velocities). Total isovolumic time - t-IVT [in s/min; calculated as: 60 – (total ejection time – total filling time)], and Tei index (t-IVT/ejection time) were also calculated.Results: Mean EF was 43±15%. The 6-MWT correlated with age (r=-0.35; p<0.001), NYHA class (r=-0.250; p=0.005), and with the blood urea level (r=-0.23; p=0.014). 6-MWT also correlated with t-IVT (r=-0.302; p=0.001) and with Tei index (r=-0.301; p=0.001). 6-MWT did not correlate with LV diastolic function parameters; E/A ratio and E wave deceleration time or with myocardial velocities.Conclusion:. In a cohort of patients with systolic heart failure exercise capacity, assessed by 6-MWT, is related to disease severity and the degree of global LV synchronous function but not ejection fraction. These findings supports the use of those easily obtained markers of dyssynchrony, t-IVT and Tei index, in regular follow up of such patients.