In recent years, there has been an increase in the prevalence and mortality from lung diseases complicated by chronic cor pulmonale in Uzbekistan. To optimize early diagnosis, adequate prevention and treatment of CCP, it is necessary to clarify the factors leading to its development and aggravating its course , . A number of authors note that in COPD there is vasoconstriction of the vessels of the pulmonary circulation, leading to hypertrophy, dilatation and failure of the right ventricle (RV) of the heart. But the question of what pathogenetic mechanisms underlie these changes in COPD has not yet been resolved. According to most researchers, in patients with chronic lung diseases, the leading factor in the development of hemodynamic changes and disorders of the diastolic function of the right ventricle of the heart are disorders of the ventilatory lung capacity, hypoxia and endothelial dysfunction , , . With prolonged hypoxia and affective state in patients with COPD, the endothelial function, which promotes vascular relaxation, is significantly reduced, which can be the cause of pulmonary vasoconstriction, the occurrence of pulmonary hypertension and right ventricular hypertrophy (RV) of the heart. When studying violations of peripheral blood flow in patients with chronic obstructive pulmonary disease, great importance is given to the vasoregulatory function of the vascular endothelium. The role of endothelial function in the pathogenesis of PH was studied mainly in patients with primary PH.