Absence of the superior vena cava: difficulties for pacemaker implantation.

Endocardial pacemaker electrode implantation can be difficult in patients with anomalous superior vena cava (SVC). Venography and CAT scan showed that the patient lacked SVC venous drainage and that systemic veins drained into the inferior vena cava through the azygos vein. A temporary stimulation electrode was placed by puncture of the femoral vein, permanent stimulation by venotomy of the epigastric vein, with the electrode inserted through the external iliac vein.