[Paradoxical embolism due to right superior vena cava draining into the left atrium].

We report a forty-six-year-old man with a past history of brain abscess managed by surgical drainage and recurrent ischemic strokes. After treatment of brain abscess, he had been on medication for symptomatic epilepsy, but had ceased medication by his judgment. He was taken to a hospital in an ambulance for an epileptic seizure. In the hospital he suffered from drug-induced renal dysfunction caused by the intravenous anti-epileptic drug, and right hemiparesis due to ischemic stroke occurred on the third hospitalization day. He was transferred to our hospital to get a treatment for renal failure. His renal function improved gradually by hemodialysis, but an ischemic stroke recurred in the right cerebellar hemisphere. Closer examinations on the mechanisms of his strokes revealed the draining of right superior vena cava (RSVC) directly into the left atrium (LA), persistent left superior vena cava (PLSVC) and atrial septal defect (ASD). He had a rare anomaly of the systemic venous return. It seemed that his repeated strokes were caused by paradoxical embolism through the draining of RSVC to LA, and air or thrombi in the infusion lines other than intravenous thrombi was thought to be an embolic cause in this case.