Lead Perforation Into the Left Internal Mammary Artery Causing Circulatory Collapse After Pacemaker Insertion

A 66-year-old woman underwent a pacemaker implantation following a symptomatic pause. The pacemaker lead inadvertently punctured the ventricle during implantation, penetrating through to the left internal mammary artery, causing slow hemorrhage. There was subsequent circulatory collapse with shock. We describe this rare yet life-threatening condition. (