Updated clinical classification of group 1 pulmonary arterial hypertension (PAH) adapted from the 6th World Symposium on Pulmonary Hypertension

1.1 Idiopathic PAH
1.2 Heritable PAH
1.3 Drug- and toxin-induced PAH
1.4 PAH associated with:
    1.4.1 connective tissue disease
    1.4.2 HIV infection
    1.4.3 portal hypertension
    1.4.4 congenital heart disease
    1.4.5 schistosomiasis
1.5 PAH long-term responders to calcium channel blockers
1.6 PAH with overt features of venous/capillaries (PVOD/PCH) involvement
1.7 Persistent pulmonary hypertension of the newborn syndrome

PVOD: pulmonary veno-occlusive disease; PCH: pulmonary capillary haemangiomatosis.