Unusual VDD-pacing.

The case of an 80-year-old woman who underwent permanent VDD-pacemaker implantation for recurrent syncope in the presence of second-degree type 2 AV-block is reported. During follow-up, low atrial sensing with AV-synchrony of only 58-73% was noted. Four years after the pacemaker implantation, the patient was hospitalized for non-cardiac reasons and the chest radiograph showed displacement of the atrial dipole into the right ventricular outflow tract (RVOT). It is hypothesized that AV-synchrony was maintained by left atrial sensing due to the anatomic proximity of the RVOT to the left atrial appendage.