Biventricular pacing and persistent left superior vena cava. Case report and review of the literature.

Persistent left superior vena cava is usually asymptomatic and does not cause any physiological problems (1). However it can severely complicate pacemaker implantation and render it sometimes impossible (2). In this case report we describe the implantation of a biventricular pacemaker using a left-sided approach in a patient with persistent left superior vena cava syndrome. A biventricular resynchronization device was used because of the reported beneficial haemodynamic effects of this pacing mode in patients with severe heart failure (3).