Integrating the Whole: Cardiopulmonary Exercise Testing

Most diagnostic tests assess the function of a single organ or organ system at rest. Conversely, exercise requires the integrated function of multiple systems under stress, including the cardiovascular, pulmonary, and musculoskeletal systems. The physical stress of exercise can expose physiological limitations not otherwise apparent at rest. This is particularly relevant for patients with respiratory and/or heart diseases in whom the increased physical demands of exercise quickly exhaust their reduced functional reserves, leading to the disabling symptoms of dyspnea, leg discomfort, and fatigue. The present chapter provides a framework for CPET performance and interpretation aimed at maximizing its clinical relevance. This approach underscores the principle that measurement of exertional symptoms, using validated scales and parameters of ventilatory control and dynamic respiratory mechanics, should be routinely used to optimize clinical CPET interpretation.