Maximal Workload and Oxygen Uptake during Exercise after Aortic-Valve Replacement

Abstract

Context:It is more feasible to assess functional capacity with an exercise test than to measure peak-exercise VO2.Objective:To assess whether maximal workload reliably predicts peak VO2.Patients:Thirty-six patients after aortic-valve replacement during routine follow-up.Design:Incremental symptom-limited cycle exercise test in the upright position with increments of 20 W/min.Setting:Out-clinic patients, university hospital.Main Outcome Measures:Maximal workload, ventilatory threshold, and peak VO2.Results:Maximal workload was 151 ± 39 W, and peak VO2, 1649 ± 486 ml/min. The correlation coefficient between maximal workload and peak VO2wasr= .92 (P< .0001). The regression equation for the estimation of peak VO2wasy= 11.7 (maximal workload in watts) – 110.7. Peak VO2calculated with this equation was 1657 ± 451 ml/min.Conclusions:Maximal workload during ergometry in the upright position reliably predicted peak VO2.