The pulmonary embolism that wasn’t: a case of asymmetric pulmonary arterial flow in Scimitar syndrome

Abstract

A 27-year-old Malaysian woman with prior history of recurrent unexplained episodes of syncope was diagnosed in adulthood with Scimitar syndrome, a rare form of partial anomalous pulmonary venous return (PAPVR). Consequently, she underwent a corrective right pulmonary vein to left atrium baffle surgery. Postoperatively, she was readmitted for pleurisy and haemoptysis, with no evidence of respiratory distress. Subsequent workup with computed tomography of pulmonary angiography (CTPA) revealed the presence of a filling defect in the right main pulmonary artery, mimicking a pulmonary embolism. However, in view of atypical presentation and altered cardiopulmonary flow dynamics, a cardiac magnetic resonance (CMR) angiography imaging was performed demonstrating patent right pulmonary artery on delayed phase acquisition with narrowed surgical baffle. The diagnosis of pulmonary embolism was revised. This case highlights the importance of understanding the pathophysiology and flow mechanics of congenital cardiovascular diseases as well as the diagnostic imaging of choice.