Persistent Left Superior Vena Cava Draining Into the Left Atrium Found During Bypass Operation.

We report the case of a 72-year-old woman who underwent urgent coronary bypass grafting (CABG). Intraoperatively a persistent left superior vena cava (PLSVC) draining into the left atrium was detected. Because of the resulting right-to-left shunt volume even after complete drainage and collapse of the right atrium, the heart was still ejecting in the absence of significant aortic insufficiency. Thorough examination revealed a PLSVC draining into the left atrium. After ligation of the PLSVC, the CABG could be performed as planned.