Double superior vena cava and anomalous left atrial drainage of persistent left SVC: A case report

Persistent left superior vena cava (PLSVC) is an uncommon developmental variation of the thoracic venous system, sometimes accompanied by a duplicated superior vena cava (SVC). While often asymptomatic when draining into the right atrium, drainage toward the left atrium could lead to a right-to-left shunt and potential compromise of whole-body oxygen delivery. This report describes a 48-year-old male patient with hypertension and chronic tobacco use who was evaluated for dyspnea and leg edema. Imaging revealed a double SVC, where the left-sided vessel connected directly to the left atrium. Despite this anomaly, the patient exhibited no significant hypoxemia or cyanosis, likely due to long-term compensatory mechanisms. This report underscores the need to consider vascular anomalies in imaging interpretation, particularly when findings are incidental. It also underscores the role of contrast-enhanced CT in identifying rare anatomical variants and the potential for such anomalies to remain clinically silent despite physiological significance.