RESUMO
Unintentional placement of a left ventricular lead through a patent foramen ovale (PFO) is an uncommon and underdiagnosed complication. Normal single- or dual-chamber permanent pacemaker implantation involves placing a lead across the tricuspid valve into the right ventricle. In a very rare case instead of the lead going into the right ventricle, it goes through the PFO and across the mitral valve into the left ventricle (LV) resulting in LV pacing. We describe a case of one of our patients who presented with syncope due to bifascicular block and underwent a dual-chamber pacemaker implantation at a local hospital. He had a background of paroxysmal atrial fibrillation and sarcoidosis. Post-procedure, he was discharged with an inadvertent lead in the LV that was not identified. Abnormal placement of LV leads can result in serious complications including thromboembolism, mitral regurgitation, and left-sided endocarditis. Treatment options include extraction of the lead or anticoagulation.
