For early recognition of pulmonary hypertension exercise doppler echocardiography will be used in all patients. Patients with elevated pulmonary arterial pressure at rest or during exercise (estimated by echocardiography), or with decreased exercise capacity (as a potential sign of pulmonary hypertension) are advised to undergo right heart catheterisation. Cardiopulmonary exercise testing and six-minute walk distance measurement are performed to measure exercise capacity. The described work-up of patients allows precise and objective hemodynamic and clinical evaluation.