Elevation of pulmonary artery (PA) pressure (i.e., mean PA pressure >22 mmHg) due to pulmonary vascular or parenchymal disease, increased left heart filling pressures, or a combination. Table 129-1 Classification of Pulmonary Hypertension lists etiologies of pulmonary hypertension (PH) by categories.
Jugular venous distention, RV lift, increased P2, right-sided S3 or S4, tricuspid regurgitation. Peripheral cyanosis and edema are late manifestations.
CXR shows enlarged central PA; may demonstrate vascular “pruning.” ECG typically indicates RV hypertrophy and RA enlargement. Echocardiogram shows RV and RA enlargement, RV hypertrophy; RV systolic pressure can be estimated from Doppler velocity of tricuspid regurgitation; echo “bubble study” identifies right-to-left intracardiac shunts that can cause Group 1 PH. Pulmonary function tests (PFTs) identify underlying obstructive or restrictive lung disease; impaired CO diffusion capacity is common. Chest CT identifies contributing interstitial lung disease or pulmonary thromboembolic disease (note that ventilation-perfusion [V/Q] scan is more sensitive for detection of chronic thromboembolism as cause of Group 4 PH). ANA titer, rheumatoid factor, anti-Scl-70 antibodies are elevated in specific collagen vascular conditions that can result in PH. HIV testing should be performed in individuals at risk. Cardiopulmonary exercise testing can differentiate pulmonary from cardiac contributions to dyspnea. Right heart catheterization assesses PA pressures, cardiac output, and pulmonary vascular resistance, quantifies underlying congenital vascular shunts, and distinguishes left-sided heart disease from pulmonary causes of PH; during procedure, response to short-acting vasodilators can be tested. Serum brain natriuretic peptide (BNP) and NT-proBNP elevation correlate with RV dysfunction and hemodynamic severity of PH.
Figure 129-1. An Algorithm to Assess for Causes of Pulmonary Hypertension summarizes a testing approach for pts with unexplained PH.
Pulmonary Arterial Hypertension (Pah) 
Represents Group 1 PH (Table 129-1 Classification of Pulmonary Hypertension), an uncommon but very serious form of PH, for which advanced pharmacologic therapies are available. Most pts with idiopathic PAH present in fourth and fifth decades, female > male predominance; may be familial. Major symptom is dyspnea, often with insidious onset. Right heart catheterization demonstrates a mean pulmonary artery pressure ≥25 mmHg, pulmonary vascular resistance >240 dyne-s/cm5 , with a mean pulmonary capillary wedge pressure ≤15 mmHg. Mean survival of PAH is 5-6 years, even with therapy.
| TREATMENT | ||
Pulmonary Arterial HypertensionLimit physical activities, use diuretics for peripheral edema, O2 supplementation if PO2 reduced. If short-acting vasodilators are beneficial during right heart catheterization, pt may benefit from high-dose calcium channel blocker (e.g., nifedipine, up to 240 mg/d, or amlodipine up to 20 mg/d); monitor for hypotension or worsening of right heart failure during such therapy. Additional approved therapies for PAH include:
For selected pts with persistent right heart failure, lung transplantation may be considered. |