Impaired hemodynamic response to exercise in HF

Peak V_O2 achieved with exercise in normal subjects and those with chronic heart failure (HF) in relation to peak leg blood flow and cardiac output (CO). These parameters were linearly related in both groups, an expected finding since peak V_O2 is determined in part by tissue perfusion. However, when compared with normals, patients with HF had lower levels of oxygen consumption, leg blood flow, and cardiac output.