[Cardiac resynchronization through a persistent left superior vena cava].

Cardiac resynchronization therapy is effective in the treatment of patients with severe heart failure and intraventricular dysynchrony. However, we are sometimes faced with the unexpected presence of a persistent left superior vena cava. We report the case of a patient with dilated cardiomyopathy and left ventricular dysynchrony in which we implanted a resynchronization pacemaker exclusively through a persistent left superior vena cava that did not communicate with the right vena cava.