Trans-septal left ventricular endocardial pacing through a persistent left-sided superior vena cava.

Cardiac resynchronization therapy (CRT) via the coronary sinus is not always possible. Left ventricular (LV) endocardial lead placement is a potential alternative, although its feasibility in patients with congenital heart disease is unknown. We report a case of endocardial LV pacing in a patient with a persistent left-sided superior vena cava. The procedure was successfully performed without complication, using standard equipment.