Double superior and inferior vena cava: unusual venous anomaly.

We report the case of a 56-year-old woman affected by recurrent paroxysmal atrial fibrillation and sick sinus syndrome. Before pacemaker implantation, a diagnosis of left superior vena cava persistency was made. After some years, at pacemaker replacement, an inferior vena cava anomaly was suspected because of the difficult progression of the lead for temporary pacing from the right femoral vein. Contrast ultrasonography strongly suggested the presence of a double inferior vena cava. The diagnosis was further confirmed by contrast computed tomography. To the best of our knowledge, this is the first description of the isolated contemporary presence of double superior and inferior venae cavae.