Pulmonary Arterial Hypertension
Posted by dkwinter

Types of PAH

WHO group 1 (Idiopathic) Pulmonary Arterial Hypertension (PAH)
WHO group 2 PAH due to left heart disease or hypoxemia
WHO group 3 PAH due to chronic lung disease (e.g. COPD, ILD)
WHO group 4 PAH due to chronic thromboembolic disease
WHO group 5

PAH due to other causes

  • hematologic (e.g. myelodysplastic syndromes)
  • systemic (e.g. sarcoidosis)
  • metabolic (e.g. glycogen storage disorders)



  • dyspnea
  • fatigue/weakness
  • exertional angina
  • syncope
  • abdominal distension/pain



  • left parasternal lift, prominent right ventricular heave
  • pansystolic murmur of tricuspid regurgitation
  • Signs of right heart failure
    • JVD
    • ascites
    • peripheral edema
    • hepatomegaly
  • Loud P2
  • Right-sided S3



  • Chest x-ray characteristically reveals bilateral pulmonary artery enlargement with attenuation of peripheral arteries
  • Transthoracic echocardiography
    • estimates pulmonary artery pressure
    • evaluates for associated right ventricular dysfunction
    • assesses for left ventricular dysfunction or valvular abnormality as a secondary cause of PAH (i.e. PAH group 2)
  • Right heart catheterization
    • is required for definitive diagnosis
      • mean pulmonary arterial pressure >= 25 mm Hg


Treatment of group 1 PAH

  • endothelin receptor antagonists (e.g. bosentan, ambrisetan)
  • phosphodiesterase-5 inhibitors (e.g. sildenafil, tadalafil)
  • prostacyclin pathway agonists (e.g. epoprostenol, treprostinil, iloprost)
  • for patients with positive vasoreactive test during right heart catheterization: calcium channel blockers (e.g. long-acting nifedipine)




COPD=chronic obstructive pulmonary disease

ILD=interstitial lung disease

JVD=jugular venous distension