Fig. 3.
Accuracy of combined oxygen (O2) pulse curve pattern and optimal peak O2 pulse criteria pattern for differentiating cardiac from noncardiac causes of exercise limitation. The Cardiac Group included patients who had abnormal results as determined by both optimal peak O2 pulse and O2 pulse curve patterns, and the Noncardiac Group included patients who had normal results as determined by both optimal peak O2 pulse and O2 pulse curve patterns. Borderline patients had abnormal or normal results as determined by only one criterion.