Introduction Pulmonary artery pressure ≥ 25 mmHg or > 35 mmHg during exercise normal = 10-14 mmHg Pulmonary hypertension has primary and secondary causes primary pulmonary hypertension a genetic mutation which predisposes to abnormal vasculature results in vascular hyperactivity and hyperplasia of smooth muscle may also involve fibrosis, thombosis of pulmonary vasculature, and endothelial cell growth poor prognosis more common in women secondary pulmonary hypertension endothelial cell dysfunction ↑ in vasoconstrictors or ↓ in vasodilators COPD destruction of lung parenchyma results in hypoxia ↓ in O2 tension results in pulmonary vessel constriction autoimmune disease (e.g. SLE) inflammation results in intimal fibrosis left-to-right shunt (e.g. ASD/VSD) ↑ blood flow results in endothelial injury sleep apnea obesity hypoventilation syndrome or living at high altitude ↓ in O2 tension results in pulmonary vessel constriction recurrent thromboemboli ↓ pulmonary vasculature mitral stenosis ↑ pressure due to backflow of blood from the left heart into the pulmonary circulation atherosclerosis result of injury to lumen as a result of ↑ pressure and proliferation of medial smooth muscle Presentation Symptoms dyspnea angina Physical examination loud P2 on auscultation right ventricular heave Evaluation CXR enlarged pulmonary arteries enlarged cardiac apex due to right ventricular hypertrophy Echocardiogram right ventricular hypertrophy dilated pulmonary artery right ventricular dilation/hypertrophy elevated estimated PA pressure Right heart catheterization: confirms PA pressure and assesses patient's response to acute vasodilator challenge for treatment stratification Prognosis/Course Chronic PH can result in severe respiratory distress cyanosis RVH (cor pulmonale) Caution with use of diuretics in patients with cor pulmonale ↑ susceptibility to ↓ cardiac output can cause acute renal failure Treatment bosentan - an endothelin inhibitor that prevents pulmonary vasculature growth