Partial anomalous pulmonary venous return: case report and review of the literature.

Isolated partial anomalous pulmonary venous return (APVR) is an uncommon finding. A patient with isolated APVR had pulmonary hypertension without demonstrable left-to-right shunting prior to anticoagulant treatment of pulmonary emboli. After anticoagulant therapy, with a fall in pulmonary pressures and resistance to near-normal levels, left-to-right shunting was then detected by oximetry and angiography. The anomaly was visualized on electron beam angiography and confirmed by conventional angiography after anticoagulant therapy. Contrary to the expected obligatory drainage of highly saturated blood associated with APVR, lack of detectable shunting was thought to be due to the obstruction of regional blood due to thromboembolism. Copyright 2003 Wiley-Liss, Inc.