SEMISUPINE CARDIOPULMONARY EXERCISE TESTI NG (CPX) IN SEDENTARY MIDDLE-AGED NORMALS

Normal values for cardiopulmonary bicycle exercise testing in semisupi ne position using a ramping protocol in a middle-aged group of untrain ed men and women are presented. We exercised 23 men and 16 women aged from 33 to 66 years without evidence of cardiopulmonary or cardiovascu lar disease and normal findings during complete heart catheterization. Clinical findings, x-ray, resting and exercise ECG, and laboratory fi ndings were normal. Exercise testing was performed using a ramping pro tocol with a work rate increase of 20 watts/min. Respiratory gas analy sis (breath-to-breath method) was performed and oxygen uptake (VO2), c arbondioxide production (VCO2), and minute ventilation (VE) were deter mined at maximal work load and at the ventilatory anaerobic threshold. Work rate increase and heart rate were continuously monitored. From t hese data oxygen pulse, the respiratory quotient (RQ), and the ventila tory equivalents VE/VO2 and VE/VCO2 were derived. Furthermore, the VO2 to work rate ratio, and the VO2 to heart rate ratio were analyzed. Ma ximal VO2 was within the 95 % confidence interval of predicted VO(2)ma x. The anaerobic threshold (V-slope method) was 60 % of VO(2)max at th e RQ of 0.81 for men and 66 % of VO(2)max at the RQ of 0.84 for women. The O-2 pulse was 100 % of the age predicted value. The VO2 to work r ate ratio was 10.7 +/- 1.4 for men and 9.7 +/- 1.2 ml/watts/min for wo men (p < 0.05). The slope of heart rate to VO2 from rest to peak exerc ise as a measure of chronotropic competence was nonlinear in 59 % of t he subjects. The VO2 to heart rate ratio below the anaerobic threshold was 2.6 +/- 0.7 for men and 3.7 +/- 1.3 beats/ml/kg for women (p < 0. 05). Normal values for cardiopulmonary exercise testing in untrained m iddle-aged men and women are important for functional clinical assessm ent in age-matched patients with cardiopulmonary limitations.