The purpose of this study is to study the differential short-term effect of nocturnal oxygen, acetazolamide tablets and nocturnal non-invasive positive pressure ventilation on symptoms, exercise capacity and nocturnal breathing disturbances in subjects with pulmonary hypertension and sleep related breathing disorders * Trial with medicinal product
Inclusion criteria: * percapillary pulmonary hypertension diagnosed by right heart catheterisation -- stable therapy and clinical condition for at least 4 weeks * sleep disordered breathing with apnea/hypopnea index \> 10 events/h and/or median nocturnal oxygen saturation \<90% Exclusion criteria: * Pregnancy * severe daytime hypoxemia (PaO2 \< 7.2 kPA) * patients with predominantly obstructive sleep apnea.