Bilateral Partial Anomalous Pulmonary Venous Return with Intact Interatrial Septum: A Case Report and Review of Literature

Introduction: Partial anomalous pulmonary venous return (PAPVR) is a rare congenital anomaly that results in a left-to-right shunt. Bilateral PAPVR is extremely rare and is usually accompanied by an atrial septal defect (ASD). Case presentation: We present a rare case of bilateral PAPVR without ASD. A 56-year-old male patient presented to the cardiology department with atypical chest pain and congested neck veins. The patient underwent echocardiography, which revealed dilated right-sided cardiac chambers and a significant left-to-right shunt. There were no signs of intracardiac shunting by echocardiography as both atrial and ventricular septa were intact. An extra-cardiac left-to-right shunt was suspected, and the patient underwent an electrocardiogram (ECG)-gated cardiac computed tomography (CT), which revealed bilateral PAPVR. In this article, we highlight the role of ECG-gated CT in detecting complex congenital heart diseases, particularly when extra-cardiac blood shunting is suspected. Conclusions: Although it is a rare cause of left-to-right shunt in the elderly, PAPVR should be considered, particularly when there is no evidence of an intracardiac shunt. It is important to note that PAPVR can occur without showing signs of pulmonary hypertension. ECG-gated CT is the preferred imaging modality when suspecting complex congenital cardiac anomalies due to its excellent spatial resolution.