An unexpected route of temporary pacing lead.

Congenital anomalies of the venous system including superior (SVC) and inferior vena cava are not uncommon. Failure of certain vessels embryogenesis results in numerous caval variations and anomalies. Anomalies of systemic venous circulation are frequently seen in patients with congenital heart disease and are sometimes incidentally recognized. However, these are usually without significant clinical implications, detection of these anomalies is necessary to avoid diagnostic pitfalls and for planning vascular interventions. We present a rare caval anomaly, a left-sided IVC with hemiazygos continuation to left SVC and coronary sinus.