Right-sided superior vena cava draining into the left atrium in a patient with persistent left-sided superior vena cava emptying into the right atrium: a case report

Background A wide range of congenital and acquired abnormalities can impact the superior vena cava (SVC), with some remaining asymptomatic. The most common anomaly is the persistent left SVC draining into the coronary sinus or right atrium, while the right SVC draining into the left atrium is rarely found. These two conditions may coexist, which is an extremely rare phenomenon. Case presentation A 38-year-old man with a history of resected astrocytoma presented with seizures and cardiac arrest. Laboratory investigations revealed leukocytosis, hyperglycemia, severe acidosis, and elevated cardiac enzymes. Transthoracic echocardiogram was performed and was unremarkable. However, a bubble study was not performed at the time. Brain imaging confirmed a diagnosis of brain micro-abscesses/embolic infarctions, while cardiac computed tomography revealed a right-sided superior vena cava draining into the left atrium with a right-to-left shunt and a persistent left superior vena cava draining into the coronary sinus. Following the discovery of right-to-left shunt on cardiac CT, a transesophageal echocardiogram and a cardiac MRI were booked. However, the patient left against medical advice to go back to his home country and seek medical care there. Conclusion In conclusion, the coexistence of dual drainage of the superior vena cava, with the right SVC draining into the left atrium and the persistent left SVC draining into the right atrium, is an extremely rare congenital anomaly. The right-to-left shunt may result in significant cerebrovascular complications requiring surgical correction, while the persistent left SVC draining into the coronary sinus may require ablation if resulted in arrhythmias.