Echocardiographic evaluation of left superior vena cava to the left atrium.

We report two cases of left superior vena cava draining directly to the left atrium in the absence of complex congenital heart disease. This is a rare finding causing a decrease in patient oxygen saturations. The location and diagnosis of this systemic venous anomaly requires diligence on the part of the cardiac sonographer, who should be able to identify the structure during the course of a thorough echocardiographic examination. Both adult and pediatric cardiac sonographers should be alerted to the possible presence of this vessel. Once the vessel has been successfully identified, repair and follow-up are relatively simple with positive patient prognosis.