Table 2.

Etiologic groups of pulmonary hypertension [1].

Etiologic group
Pulmonary arterial hypertension (group 1)	7 (21%)
Idiopathic	6 (18%)
Portal hypertension	1 (3%)
Associated with lung disease and/or hypoxemia (group 3)	16 (47%)
Chronic obstructive pulmonary disease	8 (23%)
Interstitial lung disease	3 (9%)
Combined pulmonary fibrosis and emphysema	3 (9%)
Other	2 (6%)
Thromboembolic obstruction (group 4)	9 (26%)
Miscellaneous (group 5)	2 (6%)

Data expressed are absolute values (percent of total).