Excerpt

Inadvertent implantation of a pacemaker lead in the left ventricle (LV) is an uncommon complication and its diagnosis requires a high index of suspicion. The incidence of malpositioned leads remains unclear, but may increase proportionally to the rising number of cardiac device implantations. A right ventricular (RV) lead can be placed inadvertently into the LV through an interatrial septum (via a patent foramen ovale, atrial septal defect, or septal perforation) [1], atrioventricular septum [2], interventricular septum (ventricular septal defect or septal perforation) [3, 4], coronary sinus (via a right atrium or persistent left superior vena cava) [5], or unintentionally a left subclavian artery (across the aortic valve along a retrograde course) [6, 7]. This may especially occur in patients with dilated hearts or previous cardiac surgery, which may make fluoroscopic examination difficult and misleading. However, inadvertent implantation of a pacemaker lead in the middle cardiac vein (MCV) [5, 8, 9] may be missed during the procedure due to the MCV anatomic course resembling an RV apical position under fluoroscopic guidance. …