An evaluation of integrated cardiopulmonary exercise testing in a pulmonary function laboratory.

Clinical exercise testing has been used mainly to assess the cardiac response to exercise. Integrative cardiopulmonary exercise tests (CPET) involving the measurement of the ventilatory, circulatory and metabolic response to exercise has largely been a research tool. We analysed the results of one hundred tests randomly chosen from a total of 472 exercise tests performed between January 1992 and June 1993 as clinical investigation in a pulmonary function laboratory. CPET was used (a) to identify the cause of effort limitation in patients where more than one illness could be relevant (26); (b) to obtain an objective measure of the exercise capacity of patients with respiratory or cardiac disease (31); (c) as monitor of response to treatment (11) and (d) in the investigation of unexplained dyspnoea (32). In 94 of the 100 cases CPET was able to provide an answer to the specific clinical question posed. In patients with unexplained dyspnoea (CPET identified a group who exhibit an inappropriate hyperventilatory response to exercise with no supportive evidence of cardiopulmonary disease. In a small minority of cases CPET gave non-specific results. We conclude that CPET is a useful investigation in the management of patients with cardiopulmonary disease and complements the various other investigations offered by a pulmonary function laboratory.