Inadvertent left ventricular pacing through the pericardium.

Inadvertent placement of a pacemaker lead in the left ventricle (LV) is a rare complication of pacing. We describe a case of inadvertent LV pacing where the ventricular lead traversed the mediastinum and accessed the heart through the posterior wall of the left atrium. Both transesophageal echo and venography were useful in understanding the course of the misplaced lead, which was removed percutaneously without complication.