Development of normal ranges for cardiopulmonary exercise testing performed using arm ergometry

Introduction: The performance of a cardiopulmonary exercise test (CPET) requires an individual to undertake a progressive, maximal exercise test to a symptom limited end point. CPET is standardly performed using a treadmill or cycle ergometer (CE). There is a growing cohort of patients in whom the performance of a CE or treadmill test is not possible. Arm ergometry (AE) is an alternative exercise modality to CE, however, AE achieves lower oxygen uptake (V̇O2) values as it involves smaller muscle groups and generates less cardiovascular stress. Current predicted equations for the interpretation of AE CPET are limited by small sample sizes, gender bias and limited age ranges. Aims: To develop predicted equations and reference ranges for AE exercise testing and to compare the results of AE CPET to those obtained from CE. Methods: Maximal CPET to volitional exhaustion was performed in a group of 116 (62 F) healthy volunteers of median age 38 (IQR 19) years, using both AE and CE with randomised testing order and a rest interval of at least 24 hours. Breath by breath gas analysis was performed using the Ultima CPX (Medical Graphics, UK) metabolic cart. Regression analysis was used to develop regression equations for AE V̇O2, work rate, anaerobic threshold and heart rate. Results: The model with dependent variable AE V̇O2 ml.min-1 and independent variables age (years), sex (0 male, 1 female) and weight (kg) fit the population with a r2 = 0.542 and adjusted r2 = 0.53. The equation estimated with this model was 1930.803 - (12.651 x age) – (756.095 x sex) + (10.507 x weight). Equations for peak work rate, anaerobic threshold and heart rate were also developed. Results demonstrated that AE exercise parameters were significantly lower than those obtained from CE. Conclusions: These findings represent the largest and most diverse set of predicted values and reference ranges for AE CPET parameters in healthy individuals to date. Implementation of these reference equations will allow AE to be more widely adopted enabling the performance and interpretation of CPET in a wider population