Anodal Capture May Prevent Cardiac Resynchronization Therapy from Working Effectively. A Case Report of Left Ventricular Lead Dislodgement

A 78-year-old man was implanted with a cardiac resynchronization therapy defibrillator. One month later, chest X-ray and electrocardiography suggested left ventricular (LV) lead dislodgement. However, the LV lead pacing threshold obtained by a programmer was unchanged because anodal capture had developed, which made it difficult to confirm the LV lead dislodgement. Radiographs obtained in the catheterization laboratory revealed that the tip of the LV lead had dislodged into the right atrium. The LV lead was relocated into another lateral coronary vein. Electrocardiography showed the QRS duration to be shorter than prior to this revision.