Relation of exercise capacity to resting arterial oxygen transport in left ventricular dysfunction

To determine the relation between arterial oxygen delivery and exercise capacity, 38 men with mild to severe chronic left ventricular (LV) dysfunction (New York Heart Association functional class II or III) were studied. All diagnostic cardiac catheterizations were performed 1 week before the exercise tests and the mean LV ejection fraction was 0.30 +/- 0.07. All patients performed graded treadmill exercise tests according to the Sheffield protocol. The relation between supine resting hemodynamic measurements did not correlate with exercise duration. Only resting cardiac output (r = 0.54, p less than 0.01) and systemic vascular resistance (r = -0.51, p less than 0.05) correlated weakly with exercise duration. However, arterial oxygen transport was highly related to exercise duration (r = 0.76, p less than 0.001) and peak oxygen consumption (r = 0.71, p less than 0.001). Thus, knowledge of calculated arterial oxygen transport can predict exercise capacity in patients with chronic LV dysfunction.