Cardiopulmonary exercising testing (CPET) has become a vital clinical tool in assessing exercise capacity and predicts outcomes with a patient with heart failure or other chronic conditions. CPET provides information relating to exercise responses of pulmonary, cardiovascular, and skeletal muscle systems that may not be adequately reflected by testing an individual organ system function. CPET provides valuable information regarding the health and functioning of the physiological systems that dictate an individual’s aerobic capacity. The insight gathered from CPET provides evidence-based recommendations on the clinical use of CPET in lung and heart disease with reverence to the assessment of exercise intolerance, prognostic assessment, as well as evaluation of therapeutic interventions, such as exercise training, drugs, and supplement oxygen. CPET has numerous clinical applications, and this article presents some of the important ones.
Cardiopulmonary exercise testing is considered a gold standard for examining the cause of exercise intolerance in patients with heart disease. Exercise intolerance refers to an individual inability to complete a required task successfully that a normal person would find tolerable. Since exercise intolerance in pulmonary and cardiac disease patients cannot be accurately predicted from physiological variables evaluated at rest, for example, forced expiratory volume in one second or body mass index, CPET becomes the best alternative. Disability testingassesses individual exercise intolerance and, where possible, establishes its cause (s).
CPET is a practical test in the identification of the cause s of exercise intolerance. There are a number of CPET response patterns that are not disease-specific, however, they point to a particular site of system dysfunction. This helps in narrowing the differential diagnostics. The absence of these expected response patterns can be considered evidence against a substantial involvement of these systems in exercise limitation. Although it is hard to establish precise mechanisms of exercise limitation in individuals without known diseases, a ventilatory limitation is unlikely because there is still a considerable reserve at peak exercise. Therefore, with ideal effort and proper assessment, the probable cause of an individual stopping exercise is dyspnea or leg fatigue. The subject may be considered to have a normal exercise tolerance. However, this scenario excludes individuals with significant COPD or lung disease and pulmonary vascular disorders, leading to exercise intolerance.
Disability testingis a crucial exercise stress testing that is normally used to assess the presence and severity of coronary ischemia, the exertion symptoms, heart rate, blood pressure response, and estimated aerobic capacity. Direct measurement of exercise respiratory gas exchange, known as cardiopulmonary exercise testing, provides additional vital clinical information that can be used to design a tailored exercise program for individuals with cardiac or pulmonary conditions. In general cardiopulmonary exercise, testing is invaluable in establishing the cause of dyspnea during exercise or exertion and in determining the normality of cardiac and pulmonary responses to exercise. The common uses of CPET include but are not limited to evaluation for exercise dyspnea, risk stratification, prognosis in heart failure, assess the results of medical and surgical therapies, and in determining disability or work-site readiness. Those are some clinical use of cardiopulmonary exercise testing.