Persistent left superior vena cava-inferior vena caval communication complicating implantation of an implantable cardioverter defibrillator.

A persistent left superior vena cava has been observed in 0.3% of the general population on autopsy. Its presence can complicate left-sided device implantation. Commonly, a LSVC connects to the right atrium via the coronary sinus. A LSVC-accessory hemiazygous-hemiazygous-inferior vena caval communication has not been described previously. The presence of such a congenital venous anomaly will prohibit a left-sided device implant.