what is pulmonary hypertension?
Definition Pulmonary hypertension is defined as a mean pulmonary arterial pressure (mPAP) ≥ 20 mmHg at rest, measured by right heart catheterization. Classification (WHO Groups of Pulmonary Hypertension) Pulmonary hypertension is classified into five groups based on underlying causes: Group Cause Group 1: Pulmonary Arterial Hypertension (PAH) Idiopathic, hereditary, drug-induced, connective tissue diseases (e.g., scleroderma) Group 2: PH due to Left Heart Disease Left ventricular failure, mitral valve disease Group 3: PH due to Lung Diseases or Hypoxia COPD, interstitial lung disease, sleep apnea Group 4: Chronic Thromboembolic PH (CTEPH) Obstruction of pulmonary arteries by chronic blood clots Group 5: PH with Unclear or Multifactorial Causes Sarcoidosis, hematologic disorders, metabolic disorders Pathophysiology Vasoconstriction of pulmonary arteries Vascular remodeling (thickening of vessel walls) Thrombosis in situ (clot formati...