ABSTRACT
The current classification (Table 16.1) comprises five groupings.
Group 1 consists of disorders that produce pulmonary arterial hypertension (PAH), defined as a condition in which the precapillary pulmonary vascular bed is the exclusive or predominant site of disease. This group includes idiopathic pulmonary arterial hypertension (IPAH), previously termed primary pulmonary hypertension (PPH), heritable pulmonary hypertension, previously termed familial pulmonary hypertension, the broad group of connective tissue diseases that are associated with pulmonary vascular disease, drugs and toxins, congenital heart disease, portal-pulmonary hypertension, and infections associated with pulmonary hypertension such as HIV infection and schistosomiasis. These conditions share many similarities, although, as discussed in chapters addressing each of these conditions, they also have unique features and characteristics.
