Predictors of inappropriate atrial sensing in long-term VDD-pacing systems

Aims The efficacy and stability of the atrial electrode sensing function is essential for maintaining atrioventricular (AV) synchrony. This study aimed to explore the long-term reliability and causes of the long-term sensing failure of VDD systems. Methods and results We enrolled all the patients with complete or high-degree AV block who received VDD pacemakers between August 1994 to January 2006 and who were followed up for more than 12 months. The interrogation parameters, including the atrial potentials (APs) and AV-synchrony ratio were acquired immediately post-implantation and at 3–6 month intervals thereafter. An inappropriate atrial sensing efficacy was defined as an AV-synchrony ratio of