Clinical classification of pulmonary hypertension (PH)

 Idiopathic PAH
 Heritable PAH
 Drug- and toxin-induced PAH
 PAH associated with:
  Connective tissue disease
  HIV infection
  Portal hypertension
  Congenital heart disease
 PAH long-term responders to calcium channel blockers
 PAH with overt features of venous/capillaries (PVOD/PCH) involvement
 Persistent PH of the newborn syndrome
2 PH due to left heart disease
 PH due to heart failure with preserved LVEF
 PH due to heart failure with reduced LVEF
 Valvular heart disease
 Congenital/acquired cardiovascular conditions leading to post-capillary PH
3 PH due to lung diseases and/or hypoxia
 Obstructive lung disease
 Restrictive lung disease
 Other lung disease with mixed restrictive/obstructive pattern
 Hypoxia without lung disease
 Developmental lung disorders
4 PH due to pulmonary artery obstructions
 Chronic thromboembolic PH
 Other pulmonary artery obstructions
5 PH with unclear and/or multifactorial mechanisms
 Haematological disorders
 Systemic and metabolic disorders
 Complex congenital heart disease

PAH: pulmonary arterial hypertension; PVOD: pulmonary veno-occlusive disease; PCH: pulmonary capillary haemangiomatosis; LVEF: left ventricular ejection fraction.