In patients with chronic obstructive pulmonary disease (COPD) the interpretation of dyspnoea also needs to consider coexisting cardiovascular disease. Cardiopulmonary exercise testing (CPET) is used to characterize pulmonary and cardiac function and limitations during exercise. The investigators hypothesise that cardiopulmonary exercise is reduced in COPD patients with coexisting cardiovascular disease as well as in more symptomatic patients and in patients with frequent exacerbations. For this purpose, 100 patients with with stable COPD are characterized by clinical characteristics, laboratory tests, lung function, electrocardiography, echocardiography and cardiopulmonary exercise testing.
