Cardiac output estimated noninvasively from oxygen uptake during exercise
Key result
Noninvasive estimation of cardiac output from oxygen uptake during progressive exercise correlated strongly with the direct Fick method (r = 0.96).
Why the study?
Does noninvasive estimation of cardiac output from oxygen uptake correlate with the direct Fick method during exercise in healthy subjects?
Population
5 healthy subjects
Comparison
Noninvasive estimation of cardiac output from… vs Direct Fick method
Design
Cross-sectional
Authors
Discussion
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Member takes
Implication
Supports noninvasive cardiac output estimation from oxygen uptake during exercise; hypothesis-generating pending validation in clinical populations.
Key Points
- To determine whether cardiac output and stroke volume can be estimated noninvasively during progressive cycle exercise from oxygen uptake and predicted arteriovenous oxygen content difference.
- Evaluated 5 healthy subjects across 10 progressive ramp cycle ergometry tests to exhaustion.
- Sampled arterial and mixed venous blood to assess blood gases and oxyhemoglobin concentration using a CO-oximeter.
- Arteriovenous oxygen difference was reliably predicted from percent maximum oxygen uptake via linear regression [C(a-v̄) = 5.72 + 0.105 × %V̇o2max; r = 0.94].
- Cardiac output calculated from the regression model correlated strongly with direct Fick measurements (r = 0.96), demonstrating a low coefficient of variation (7–9%) between the lactic acidosis threshold and peak V̇o2.
Study Design
Type
Observational (n=5)
Structured PICO
Does noninvasive estimation of cardiac output from oxygen uptake correlate with the direct Fick method during exercise in healthy subjects?
P
Population
5 healthy subjects
I
Intervention
Noninvasive estimation of cardiac output from oxygen uptake (VO2) during progressively increasing ramp pattern cycle ergometry exercise
C
Comparator
Direct Fick method
O
Outcome
Correlation between estimated cardiac output and cardiac output determined by the direct Fick methodsurrogate
Main Result
Effect estimate: r = 0.96
Cardiac output and stroke volume can be accurately estimated noninvasively during progressive exercise testing from measured oxygen uptake.
Cite This Study
Stringer et al. (1997) conducted an observational in Healthy (n=5). Noninvasive estimation of cardiac output from oxygen uptake vs. Direct Fick method was evaluated on Correlation of estimated cardiac output with direct Fick method (r = 0.96). Noninvasive estimation of cardiac output from oxygen uptake during progressive exercise correlated strongly with the direct Fick method (r = 0.96).