Cardiopulmonary exercise testing in systolic heart failure: from basic to advanced practice

Cardiopulmonary exercise testing (CPET) is a specialized subtype of exercise testing that provides a more accurate and objective measure of cardiorespiratory fitness (CRF). CPET relies on measurement of ventilatory gases during exercise, i.e., a non-invasive procedure that involves the acquisition of expired ventilation and concentrations of oxygen (O₂) and carbon dioxide (CO₂) during progressive exercise. The non-invasive measurement of ventilation and expired gases permits the most accurate and reproducible quantification of CRF, a grading of the etiology and severity of impairment, and an objective assessment of the response to an intervention. Moreover, a particularly large volume of research has been directed toward the utility of CPET as a prognostic tool; CPET is a scientifically sound and therefore clinically valuable method for accurately estimating prognosis in various disease states. Although still underutilized, CPET has gained popularity not only due to the recognition of its clear value in the functional assessment of patients with cardiovascular, pulmonary and musculoskeletal disease/disorders, but also because technological advances (e.g., rapid response analyzers and computer-assisted data processing) have made this modality easier to use.