Delayed attainment of peak oxygen consumption after the end of exercise in patients with chronic heart failure
Introduction
Exercise capacity is reduced in patients with chronic heart failure (CHF) [1]and peak oxygen consumption is recognized as one of the most important prognostic variables in this setting [2]. The accuracy of peak exercise oxygen consumption measurement is therefore critical: a 20% error may suggest different likely outcomes and have important therapeutic implications. In patients with severe CHF, we have found that oxygen consumption sometimes reaches its maximal value some time after the end of exercise. In this study, we tried to characterize these patients and to understand the reasons for these findings.
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Patients and methods
We prospectively analyzed the exercise response of CHF patients referred to the exercise test laboratory of our cardiology department between January and May 1995, with the aim of determining whether peak oxygen consumption may be attained after end-exercise.
Results
The heart failure patients (groups 1 and 2) were older than the normal subjects (P<0.05). They was no significant difference between the two heart failure groups regarding age, body weight or maximal predicted oxygen consumption. Compared with group 2 patients, patients in group 1 had significantly poorer functional status (NYHA class 3.0±0.2 vs. 2.4±0.5) (Table 1) and lower end-exercise Vo2 (1156±251 vs. 1535±508 ml/min, corresponding to 59±13% and 70±19%, respectively, of predicted values);
Discussion
This study shows that a large proportion of CHF patients performing a graded bicycle exercise test attain their highest Vo2 value after exercise has ended; this would have been overlooked had gas analysis not also been performed during recovery. The increment in Vo2 after exercise was 10% on average above the end-exercise Vo2 and as high as 30% (Fig. 1 and Fig. 2). Thus, when a cardiopulmonary exercise test is used to guide the indication for cardiac transplantation, this underestimation of
Conclusions
Slow kinetics of Vo2 increase on graded exercise may delay the attainment of peak Vo2 beyond end-exercise in patients with severe CHF. This underlines the limitations of peak Vo2 in heart failure. Gas analysis should also be performed during the recovery phase of exercise if actual peak Vo2 is not to be underestimated, especially in patients with severe heart failure referred for heart transplantation. The relative prognostic value of end-exercise and peak-exercise Vo2 remains to be determined.
References (22)
- Weber K, Kinasewitz G, Janicki J, Fishman A. Oxygen utilisation and ventilation during exercise in patients with...
- Cohn J, Johnson G, Shabetai R et al. for the V-HeFT VA Cooperative Study Group. Ejection fraction, peak oxygen...
- Wasserman K, Hansen J, Sue D, Whipp B. Normal values. In: Wasserman K, Hansen J, Sue D, Whipp B, eds. Principles of...
- Wasserman K, Whipp B, Koyal S, Beaver W. Anaerobic threshold and respiratory gas exchange during exercise. J Appl...
- Cohen-Solal A, Benessiano J, Himbert D, Paillole C, Gourgon R. Ventilatory threshold during exercise in patients with...
- Beaver W, Wasserman K, Whipp B. A new method for detecting anaerobic threshold by gas exchange. J Appl Physiol...
- Cohen-Solal A, Chabernaud J, Gourgon R. Comparison of oxygen uptake during bicycle exercise in patients with chronic...
- Cohen-Solal A, Laperche T, Morvan D, Geneves M, Caviezel B, Gourgon R. Prolonged kinetics of recovery of oxygen...
- Riley M, Porszasz J, Stanford CF, Nicholls DP. Gas exchange responses to constant work rate exercise in chronic cardiac...
- Sietsema K, Ben-Dov I, Zhang Y, Sullivan C, Wasserman K. Dynamics of oxygen uptake for submaximal exercise and recovery...
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