MediAI

  1. Introduction The left superior vena cava (LSVC) is among the most common thoracic venous anomalies, reported in approximately 0.3–0.5% of the general population. Normally, the right superior vena cava (RSVC) serves as the principal venous channel, directing deoxygenated blood from the head and upper extremities into the right atrium. However, due to embryologic variations, a persistent left-sided superior vena cava may remain. In most cases, the LSVC drains into the coronary sinus, typically without clinical consequences. In some patients, however, anomalous drainage into the left atrium or, as in this case, into the right superior vena cava may occur. Such variations, if unrecognized, may lead to complications during cardiac catheterization, central venous line placement, cardiac surgery, or pacemaker lead insertion. This case demonstrates a rare anomaly in which the LSVC courses inferior to the aortic arch and drains directly into the RSVC — a highly unusual pattern scarc...