Atrial Lead Dislodgement with a DDD Pacemaker

A 48-year-old man with previous aortic valve surgery and aortic root repair had a DDD pacemaker inserted (using transvenous leads) for the treatment of complete heart block. An atrial J active fixation electrode was used. Four weeks following implantation the patient returned with an unusual electrocardiographic rhythm demonstrating two separate QRS morphologies. Both PA and lateral chesf x-ray failed to demonstrate a change in lead position. The MARKER CHANNELTM of the DDD pulse generator confirmed that the alternating QRS morphologies were due to atrial lead dislodgement. Although uncommon, displacement of atrial active fixation leads may occur and lead to unusual electrocardiographic rhythms. Use of a MARKER CHANNELTM may aid in the diagnosis.