Abstract
The Eustachian valve (EV) is an embryological remnant of the inferior vena cava (IVC) valve thatprenatally directs the oxygenated blood from the IVC across the patent foramen ovale (PFO) into systemic circulation. Even when the EV is prominent, it is usually considered to be a benign finding in the absence ofassociated cardiac anomalies. We present a patient with PFO whose prominent EV increased spontaneousright-to-left shunt and promoted paradoxical cerebral embolism. EVs may persist more frequently than expected in Japan and should be considered adjunctive risk factors for paradoxical cerebral embolismirrespective of their size in patients with PFO.
