Mean ± SEM hemodynamic measurements at rest (time 0) and during the first 6 minutes of exercise for patients with heart failure, stratified by mean response time (MRT) and control subjects. MRT was derived using hemodynamic measurements corresponding to unloaded exercise, performed at minutes 0 to 3 of exercise. A, Right atrial pressure (RAP); B, mean pulmonary artery pressure (mPAP); C, pulmonary capillary wedge pressure (PCWP); D, Cardiac output. * Denotes p<0.05 for comparison of average hemodynamic measurements during exercise for MRT< 60 sec vs. MRT ≥ 60 sec.