Effect of duration of data averaging interval on reported peak VO₂ in patients with heart failure

Abstract

Aim: To describe the effect of the duration of the data averaging interval on the calculated peak oxygen uptake (VO₂) reported from a symptom-limited maximal exercise test in patients with heart failure. Methods: Maximal exercise test results from 275 patients diagnosed with stable heart failure due to left ventricular systolic dysfunction (ejection fraction < 45%; age: 45-75 years; peak VO₂: 8.0-20.0 mL/kg/min), were examined. Sampling rates of 10, 20, 30 and 60 s were used to calculate peak VO₂, which was identified as the highest interval value that occurred during the final minute of exercise or the first interval in immediate recovery. ... Conclusions: Sampling rate method has a significant effect on calculated peak VO₂ and RER. We suggest that laboratories standardize their sampling rate method to ensure consistency.