REPRODUCIBILITY OF PEAK OXYGEN-UPTAKE AND ANAEROBIC THRESHOLD DURING CARDIOPULMONARY EXERCISE TESTING IN PATIENTS WITH CONGESTIVE-HEART-FAILURE

A prerequisite for the clinical utility of cardiopulmonary exercise te sting is high reproducibility of gas-exchange characteristics. Therefo re, we studied reproducibility of peak oxygen uptake and anaerobic thr eshold during bicycle-exercise stress testing in 34 patients with cong estive heart failure in NYHA classes II and III. Additionally, we anal yzed interobserver variability with regard to anaerobic threshold meas ured with the V-slope method. Correlations of results between two exer cise stress tests were high concerning peak oxygen uptake and anaerobi c threshold (r = 0.871 and r = 0.917, respectively). For both measures , however, 90% percentile of the relative difference between tests was 25% and 22%, respectively. Correlation between two observers with reg ard to the anaerobic threshold was high (r = 0.985). We conclude that reproducible determination of peak oxygen uptake and anaerobic thresho ld is possible in heart-failure patients. In individual subjects, howe ver, considerable variation of results may occur during serial exercis e testing. Interobserver variability with regard to anaerobic threshol d is low.