Asymptomatic malposition of a pacing lead in the left ventricle: the case of a woman untreated with anticoagulant therapy for eight years.

: We report the case of a woman with a low-rate atrial fibrillation and a wire lead inadvertently inserted in the left ventricle through an ostium secundum defect. The malposition of the lead was diagnosed 8 years after the procedure on the basis of the presence of a right bundle branch block pattern of the paced QRS, at echocardiography and at chest X-ray. The patient, who was neither on antiaggregant nor anticoagulant therapy, was asymptomatic. Biventricular pacing is a useful tool in the therapy of patients with severe chronic heart failure and intraventricular conduction delay but the insertion of the lead in the left ventricle through the coronary sinus is not always feasible. Because a patent foramen ovale is a frequent occurrence in the adult population, we suggest that in case of an unsuccessful catheterization of the coronary sinus, the physician should search for a patent foramen ovale through which to introduce the wire lead into the left ventricle, especially if the patient is already receiving anticoagulant therapy.