TY - JOUR
T1 - Are oxygen uptake kinetics in chronic heart failure limited by oxygen delivery or oxygen utilization?
AU - Kemps, H.M.C.
AU - Schep, G.
AU - Zonderland, M.L.
AU - Thijssen, E.J.M.
AU - Vries, de, W.R.
AU - Wessels, B.
AU - Doevendans, P.A.F.M.
AU - Wijn, P.F.F.
PY - 2010
Y1 - 2010
N2 - Background: The delay in O2 uptake kinetics during and after submaximal physical activity (O2 onset and recovery kinetics, respectively) correlates well with the functional capacity of patients with chronic heart failure (CHF). This study examined the physiological background of this delay in moderately impaired CHF patients by comparing kinetics of cardiac output (Q?) and O2 uptake (V?O2 ). Methods: Fourteen stable CHF patients (New York Heart Association class II-III) and 8 healthy subjects, matched for age and body mass index, were included. All subjects performed a submaximal constant-load exercise test to assess O2 uptake kinetics. Furthermore, in 10 CHF patients Q? was measured by a radial artery pulse contour analysis method, which enabled the simultaneous modelling of exercise-related kinetics of Q? and V?O2 . Results: Both O2 onset and recovery kinetics were delayed in the patient group. There were no significant differences between the time constants of Q? and V?O2 during exercise-onset (62 -Ý 25- s versus 59 -Ý 28- s, p = 0.51) or recovery (61 -Ý 25- s versus 57 -Ý 20- s, p = 0.38) in the patient group, indicating that O2 delivery was not in excess of the metabolic demands in these patients. Conclusion: The delay in O2 onset and recovery kinetics in moderately impaired CHF patients is suggested to be due to limitations in O2 delivery. Therefore, strategies aimed at improving exercise performance of these patients should focus more on improvements of O2 delivery than on O2 utilization. -© 2008 Elsevier Ireland Ltd. All rights reserved
AB - Background: The delay in O2 uptake kinetics during and after submaximal physical activity (O2 onset and recovery kinetics, respectively) correlates well with the functional capacity of patients with chronic heart failure (CHF). This study examined the physiological background of this delay in moderately impaired CHF patients by comparing kinetics of cardiac output (Q?) and O2 uptake (V?O2 ). Methods: Fourteen stable CHF patients (New York Heart Association class II-III) and 8 healthy subjects, matched for age and body mass index, were included. All subjects performed a submaximal constant-load exercise test to assess O2 uptake kinetics. Furthermore, in 10 CHF patients Q? was measured by a radial artery pulse contour analysis method, which enabled the simultaneous modelling of exercise-related kinetics of Q? and V?O2 . Results: Both O2 onset and recovery kinetics were delayed in the patient group. There were no significant differences between the time constants of Q? and V?O2 during exercise-onset (62 -Ý 25- s versus 59 -Ý 28- s, p = 0.51) or recovery (61 -Ý 25- s versus 57 -Ý 20- s, p = 0.38) in the patient group, indicating that O2 delivery was not in excess of the metabolic demands in these patients. Conclusion: The delay in O2 onset and recovery kinetics in moderately impaired CHF patients is suggested to be due to limitations in O2 delivery. Therefore, strategies aimed at improving exercise performance of these patients should focus more on improvements of O2 delivery than on O2 utilization. -© 2008 Elsevier Ireland Ltd. All rights reserved
U2 - 10.1016/j.ijcard.2008.12.088
DO - 10.1016/j.ijcard.2008.12.088
M3 - Article
C2 - 19168233
SN - 0167-5273
VL - 142
SP - 138
EP - 144
JO - International Journal of Cardiology
JF - International Journal of Cardiology
IS - 2
ER -