The cardiopulmonary exercise test (CPX) is an essential examination for detecting pathophysiological derangement and determining treatment policy because it clarifies not only the changes of hemodynamics but also abnormality in the whole body during exercise where heart disease patients often feel symptoms.

To utilize CPX effectively, we must understand each parameter, such as peak oxygen uptake (peak VO₂), peak VO₂/HR, and VE/VCO₂. In addition, comparison of each parameter, for example, peak VO₂ and VE/VCO₂, and peak VO₂ and peak VO₂/HR, is useful to detect the pathophysiological abnormalities.

In this article, I will describe how CPX should be used in clinical settings.