OBJECTIVE—To describe the kinetics of metabolic gas exchange at the onset and offset of low level, constant work exercise in patients with chronic heart failure.
SETTING—Tertiary referral centre for cardiology.
PATIENTS—10 patients with chronic heart failure and 10 age matched controls.
METHODS—Each subject undertook maximum incremental exercise testing with metabolic gas exchange measurements, and a fixed load exercise test at 25 watts with metabolic gas exchange measurements before, during, and after the test. A monoexponential curve was fitted to the data to describe the kinetics of gas exchange at onset and offset of fixed load exercise.
OUTCOME MEASURES—Peak oxygen consumption; time constants of onset and offset for metabolic gas exchange variables during constant load exercise.
RESULTS—Peak oxygen consumption (mean (SD)) was higher in controls (26.1 (4.3) v 15.3 (5.3) ml/kg/min; p