Persistent left superior vena cava with absent right superior vena cava: a difficult cardiac pacemaker implantation.

An absent right superior vena cava associated with a persistent left superior vena cava (PLSVC) is a rare and generally asymptomatic congenital malformation. It is usually discovered incidentally during a pacemaker (PM) implantation. We report here a successful PM implantation using a left subclavian approach through the coronari sinus via a PLSVC, with a 2-year follow-up showing a still appropriate function of the device. We discuss the clinical usefulness of peripheral phlebography in the operating room for delineating precisely the venous anatomy, as well as the role of shaped stylets and active fixation leads to overcome technical difficulties.