Use of the Wasserman equation in optimization of the duration of the power ramp in a cardiopulmonary exercise test: a study of Brazilian men

• Published in: Brazilian journal of medical and biological research Vol. 48; no. 12; pp. 1136 - 1144
• Main Authors: Costa, D C, Santi, G L de, Crescêncio, J C, Seabra, L P, Carvalho, E E V, Papa, V, Marques, F, Gallo Junior, L, Schmidt, A
• Format: Journal Article
• Language: English
• Published: Brazil Associacao Brasileira de Divulgacao Cientifica (ABDC) 01.12.2015; Associação Brasileira de Divulgação Científica
• Subjects: Adult; Aged; Algorithms; BIOLOGY; Brazil; Brazilians; Cardiopulmonary exercise test; Cardiovascular diagnostic techniques; Case-Control Studies; Clinical Investigation; Coronary artery disease; Coronary Artery Disease - physiopathology; Coronary heart disease; Exercise Test - methods; Exercise Test - standards; Exercise tests; Health aspects; Humans; Male; MEDICINE, RESEARCH & EXPERIMENTAL; Middle Aged; Oxygen Consumption - physiology; Physical fitness; Sedentary Behavior; Spirometry - methods; Statistics, Nonparametric; Wasserman equation; Cardiopulmonary exercise test; Cardiovascular diagnostic techniques; Wasserman equation; Coronary artery disease
• ISSN: 0100-879X; 1414-431X; 1414-431X
• DOI: 10.1590/1414-431X20154692

This study aimed to analyze the agreement between measurements of unloaded oxygen uptake and peak oxygen uptake based on equations proposed by Wasserman and on real measurements directly obtained with the ergospirometry system. We performed an incremental cardiopulmonary exercise test (CPET), which was applied to two groups of sedentary male subjects: one apparently healthy group (HG, n=12) and the other had stable coronary artery disease (n=16). The mean age in the HG was 47±4 years and that in the coronary artery disease group (CG) was 57±8 years. Both groups performed CPET on a cycle ergometer with a ramp-type protocol at an intensity that was calculated according to the Wasserman equation. In the HG, there was no significant difference between measurements predicted by the formula and real measurements obtained in CPET in the unloaded condition. However, at peak effort, a significant difference was observed between oxygen uptake (V˙O2)peak(predicted)and V˙O2peak(real)(nonparametric Wilcoxon test). In the CG, there was a significant difference of 116.26 mL/min between the predicted values by the formula and the real values obtained in the unloaded condition. A significant difference in peak effort was found, where V˙O2peak(real)was 40% lower than V˙O2peak(predicted)(nonparametric Wilcoxon test). There was no agreement between the real and predicted measurements as analyzed by Lin's coefficient or the Bland and Altman model. The Wasserman formula does not appear to be appropriate for prediction of functional capacity of volunteers. Therefore, this formula cannot precisely predict the increase in power in incremental CPET on a cycle ergometer.