Pulmonary arterial thrombosis in secundum atrial septal defect.

Nineteen adolescent or adult patients with secundum atrial septal defect (ASD) underwent pulmonary arteriography to evaluate the presence of proximal pulmonary arterial (PA) thrombosis. This procedure demonstrated proximal PA thrombosis in 8 patients (group 2). These patients had a distinctive hemodynamic profile, consisting primarily of significant PA hypertension. None of the 11 patients with normal angiograms (group 1) had severe PA hypertension (p less than 0.0001). Proximal PA thrombosis appears to be the major factor in the development and progression of PA hypertension in adult patients with ostium secundum ASD. Pulmonary angiography should be undertaken in all adult patients with ostium secundum ASD who have at least moderate PA hypertension. Long-term anticoagulation is advocated for patients with PA thrombosis irrespective of a decision for surgical intervention.