Pulmonary arterial hypertension (PAH) is a serious condition caused by the damage of the small pulmonary vessels, leading to the increase of pulmonary artery pressure, pulmonary vascular resistance, development of right ventricular failure and death. PAH is one of the actual problems of modern medicine due to low survival rate, rapid disability of the patients and a high cost of treatment. PAH is one of the leading causes of death in systemic sclerodermia (SSD). PAH associated with scleroderma is a unique phenotype combining the manifestations of both SSD and PAH, the pathogenetic mechanisms of which modify the clinical picture and the course of these conditions. Timely diagnosis and treatment of PAH show significant effect on survival rat...