Pulmonary Hypertension

Pulmonary hypertension is a condition where the blood pressure in the lungs' arteries becomes abnormally high. This affects the pulmonary circulation, which is responsible for carrying blood from the heart to the lungs to pick up oxygen. When the pressure is too high, the heart has to work harder to pump blood through the lungs, which can lead to shortness of breath, fatigue, and chest pain. Over time, this extra strain can cause the heart to weaken and fail. The condition involves changes in the blood vessels of the lungs, including narrowing and stiffening, which reduce blood flow. It can result from various causes, including heart or lung diseases, or it may occur on its own. Early symptoms are often subtle but can progress to serious health problems if untreated.

Pulmonary hypertension is defined as a mean pulmonary arterial pressure of 20 mm Hg or greater at rest, measured by right heart catheterization. It results from increased resistance in the pulmonary vasculature due to vascular remodeling, vasoconstriction, or thrombosis. The condition can be classified into five groups based on etiology, including pulmonary arterial hypertension (PAH), left heart disease, lung diseases/hypoxia, chronic thromboembolic disease, and unclear multifactorial mechanisms. The pathophysiology involves endothelial dysfunction, smooth muscle proliferation, and inflammation leading to increased pulmonary vascular resistance and right ventricular overload. Clinically, it manifests with exertional dyspnea, fatigue, and signs of right heart failure. It is a progressive disease with significant morbidity and mortality if untreated.