Figure 2. Comparison of the accuracy of the acetylene (C₂H₂) rebreathing technique vs thermodilution method for the assessment of Qc in both healthy patients and those with clinical disease in the supine position at rest.

A, Accuracy of C₂H₂ rebreathing for estimation of Qc vs thermodilution in healthy patients; (B) Accuracy of C₂H₂ rebreathing for estimation of Qc vs thermodilution in a clinical population. Qc indicates cardiac output.