Pulmonary Arterial Hypertension: A Review Article

Pulmonary arterial hypertension (PAH) is characterized by the mean pulmonary artery pressure of more than 25 mmHg and pulmonary artery wedge pressure of less than 15 mmHg evidenced by right-heart catheterization. In the classification of PAH, some subgroups are defined as primary or secondary PAH based on the underlying etiologies of the disease. Early episodes of PAH have been reported to occur at younger ages and in women in idiopathic or familial forms with the survival rate of 1-3 years. According to recent registries, the affected patients are older and have better survival rates. Some of the key elements in the pathophysiology of PAH include intima and media proliferation, vascular remodeling, and blood coagulation, which could increase the defiance of pulmonary vascularity, so that the cellular and molecular pathways would be able to induce PAH through specific mechanisms. Although no pathognomonic signs and symptoms have been reported in the literature, the most prominent manifestations of PAH are associated with disorders such as heart failure. Currently, PAH is known as a severe and occasionally life-threatening multifactorial clinical condition. Considering endothelial dysfunction, vasoconstriction, inflammatory reactions, and platelet aggregation as the main pathophysiological arms of the disease, specific treatment approaches have been proposed to inhibit these manifestations. These methods result in the effective treatment response, as well as the proper early and late outcomes of PAH. Due to the high incidence of cardiovascular diseases and the associated progressive life-threatening conditions, such as heart failure and PAH in the Iranian population, identification of the etiological, pathophysiological, diagnostic, and novel therapeutic approaches for PAH is essential to the proper management of this clinical condition