Etiologies-pulmonary hypertension
Primary pulmonary arterial HTN (PAH) (group 1)
Precapillary PHT PCWP ≤15 mmHg ↑ transpulm grad ↑ PVR
- Idiopathic (IPAH): yearly incidence 1–2 per million; mean age of onset 36 y (♂ older than ♀); ♂: ♀ = ~2:1, usually mild ↑ in PAP
- Familial (FPAH)
- Associated conditions (APAH)
- Connective tissue dis.: CREST, SLE, MCTD, RA, PM, Sjögren
- Congenital L→R shunts: ASD, VSD, PDA
- Portopulmonary HTN (? 2° vasoactive substances not filtered in ESLD; ≠ hepatopulmonary syndrome)
- HIV; drugs & toxins: anorexic agents, SSRIs, l-tryptophan
- Pulmonary veno-occlusive disease: ? 2° chemo, BMT; orthopnea, pl eff, CHF, nl PCWP; art vasodil. worsen CHF (AJRCCM 2000;162:1964)
- Pulmonary capillary hemangiomatosis
Left heart disease (group 2). ↑ PCWP
- Left atrial or ventricular (diastolic or systolic) dysfunction
- Left-sided valvular heart disease (eg, MS/MR)
Lung diseases and/ or chronic hypoxemia (group 3)
- COPD
- Alveolar hypoventilation (eg, NM disease)
- ILD
- Chronic hypoxemia (eg, high altitude)
- Sleep apnea
- Developmental abnormalities
Chronic thrombo- embolic dis (group 4)
- Prox or distal PEs; ~½ w/o clinical h/o PE (NEJM 2011;364:351)
- Nonthrombotic emboli (tumor, foreign body, parasites)
Miscellaneous/ Multifactorial (group 5)
- Sarcoidosis, histiocytosis X, LAM, schistosomiasis, ESRD
- Compression of pulm vessels (adenopathy, tumor, fibrosing mediastinitis, histoplasmosis, XRT)
- Other: thyroid dis., glycogen storage dis., Gaucher dis, HHT, sickle cell, etc., chronic myeloprolif d/o, splenectomy