Partial anomalous pulmonary venous return (PAPVR) is a rare congenital cardiovascular condition in which some of the pulmonary veins, but not all, drain into the systemic circulation rather than into the left atrium.
- in ~40% of patients with right-sided PAPVR, an atrial septal defect is seen
- more rarely it is seen with ostium primum defect, a subtype of atrioventricular defects
Chest radiographic features are particular to each subtype of PAPVR. The abnormal vein is rarely identified, except in cases of Scimitar syndrome. Pulmonary venous congestion can be seen if the venous drainage is obstructed.
Cardiomegaly can also be seen if significant abnormal intracardiac venous drainage occurs.
Complications: Patients with large shunts may present with symptoms of dyspnea, chest pain and palpitations, signs like tachycardia and murmur can be encountered. Cases of secondary pulmonary arterial hypertension have been reported.
Scimitar syndrome is characterised by a hypoplastic lung that is drained by an anomalous vein into the systemic venous system. It is a type of partial anomalous pulmonary venous return and is one of the several findings in congenital pulmonary venolobar syndrome.
It is essentially a combination of pulmonary hypoplasia and partial anomalous pulmonary venous return (PAPVR). It almost exclusively occurs on the right side.