RESUMEN
Persistent left superior vena cava (PLSVC) is one of the commonest venous anomalies of thoracic venous system. These cases usually have normal right sided superior vena cava (SVC). Patients with PLSVC are often asymptomatic hence, it is diagnosed as an incidental finding during procedures like central venous line placement or pacemaker implantation. We report here a case that was taken to catheterization laboratory for pacemaker implantation. Due to PLSVC, we struggled to advance pacing lead into right ventricular apex. We thought of right subclavian vein access but contrast medium injection revealed absent right sided SVC. So procedure was abandoned and finally epicardial placement of the pacing lead was done through subxiphoid laparotomy incision next morning. This case report highlights a rare variant of PLSVC with absent right sided SVC in structurally normal heart and emphasizes the need of pre-procedure assessment of venous anatomy.