[Left Internal Thoracic Artery Injury due to Lead Perforation After Pacemaker Implantation:Report of a Case].

Perforation of a pacemaker lead is a serious life-threatening complication. Most cases involve the heart alone and rarely involve adjacent organs. The day after the pacemaker was implanted, the patient suddenly became hypotensive and went into shock, and a computed tomography (CT) scan showed an anterior mediastinal hematoma due to bleeding from the left internal thoracic artery. We report a case in which emergency surgery was performed to save the patient's life after assuming that the hemorrhage was caused by a lead leading hemorrhage.