 Pulmonary hypertension PH is a life-threatening cardiovascular disease characterized by pathological elevation of mean pulmonary arterial pressure mPAP 25 mmHg at rest. mPAP 20 mmHg is defined as normal, values in the range between 21-24 mmHg are described as borderline PH diagnosed by right heart catheterization. Based on the etiology, PH is assigned to 5 groups WHO, Data Point, 2008, whereas classification of disease is an important prognostic and therapy-deciding criterion. 