Persistent Left Superior Vena Cava Mimicking Central Venous Catheter Malposition After Left Internal Jugular Access: A Case Report.

Persistent left superior vena cava (PLSVC) is the most common congenital thoracic venous anomaly and is usually clinically silent. We report a critically ill patient in whom PLSVC was identified after left internal jugular central venous catheter placement. Chest radiography showed a vertically oriented catheter along the left mediastinum without expected midline crossover, raising concern for malposition. Review of prior imaging confirmed PLSVC draining into the coronary sinus. Recognition of this variant prevented unnecessary catheter removal and repeat instrumentation, underscoring the importance of correlating procedural findings with imaging during left-sided venous access.