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 lists etiologies of pulmonary hypertension (PH) by categories.
TABLE 129-1Classification of Pulmonary Hypertension ||Download (.pdf) TABLE 129-1 Classification of Pulmonary Hypertension
Pulmonary Arterial Hypertension
Heritable (mutations/familial cases)
Collagen vascular diseases (e.g., scleroderma, SLE, rheumatoid arthritis)
Congenital systemic to pulmonary shunts (e.g., ventricular septal defect, patent ductus arteriosus, atrial septal defect)
Drugs or toxins (e.g., fenfluramine)
Pulmonary Hypertension Due to Left Heart Disease
LV systolic or diastolic dysfunction
Left-sided valvular disease
Pulmonary Hypertension Due to Lung Disease or Hypoxia
Chronic obstructive lung disease
Interstitial lung disease
Chronic Pulmonary Thromboembolic Disease
Chronic pulmonary embolism
Systemic conditions (e.g., sarcoidosis, pulmonary histiocytosis)
Hematologic conditions (e.g., myeloproliferative diseases)
Exertional dyspnea, fatigue, angina (due to RV ischemia), syncope, peripheral edema.
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 summarizes a testing approach for pts with unexplained PH.
An algorithm to assess for causes of pulmonary hypertension. In the absence of an identifiable etiology, idiopathic pulmonary arterial hypertension would be suspected. ASD, atrial septal defect; COPD, chronic obstructive pulmonary disease; HIV, human immunodeficiency virus; IPAH, idiopathic pulmonary arterial hypertension; PDA, patent ductus arteriosus; PFTs, pulmonary function tests; RF, rheumatoid factor; Scl-70, anti-topoisomerase 1 antibodies; V/Q, ventilation/perfusion; ...