Inadvertent implantable cardioverter defibrillator lead malpositioning in the left ventricle via a patent foramen ovale: a case report and review of the literature

Implantable cardioverter defibrillators (ICDs) play a central role in the prevention of sudden cardiac death. Although implantation is generally safe, rare but clinically significant complications may occur. One such complication is inadvertent placement of a transvenous ICD lead into the left ventricle via a patent foramen ovale (PFO), which carries a risk of systemic thromboembolism and may remain clinically silent for prolonged periods. We report a case of an ICD lead malpositioned in the left ventricle through a PFO, detected 17 months after implantation during transthoracic echocardiography performed for worsening dyspnoea. Imaging demonstrated the lead traversing the interatrial septum and mitral valve into the left ventricle. The patient underwent successful transvenous extraction and reimplantation of a new right ventricular lead without complications. This case highlights the limitations of electrocardiographic clues alone and underscores the importance of multimodality imaging and meticulous implantation technique. A focused narrative review integrates current literature regarding mechanisms, diagnostic strategies, management options, and preventive considerations.