Table 2.

RMSE from the exponential model curve fit of on-transient pulmonary V̇o₂ kinetics in both heart failure patients and age-matched healthy control subjects

	Healthy Control Subjects		Heart Failure Patients
RMSE	PLB	FNT	PLB	FNT
Phase I duration (25 s)
Single exponential	0.040 ± 0.011	0.045 ± 0.022	0.052 ± 0.014	0.050 ± 0.014
Double exponential	0.045 ± 0.009	0.048 ± 0.016	0.051 ± 0.015	0.048 ± 0.015
Single-exponential phase II pulmonary V̇o2 on-kinetics curve fit
Phase I duration, s
Model 1 (15 s)	0.045 ± 0.010	0.046 ± 0.021	0.054 ± 0.015	0.052 ± 0.013
Model 2 (25 s)	0.040 ± 0.011	0.045 ± 0.022	0.052 ± 0.014	0.051 ± 0.014
Model 3 (35 s)	0.038 ± 0.012	0.042 ± 0.019	0.050 ± 0.013	0.048 ± 0.013

Data are expressed as means ± SD. Phase I durations of 15-s, 25-s, or 35-s length correspond to removal of data from time = 0 to 10, 20, or 30 s, respectively. RMSE, root mean square error; PLB, placebo experimental arm; FNT, fentanyl experimental arm.