Dependency to Pacemaker in Patients with Normal Ejection Fraction, who is more at Chemical Risk

Background: Although there is a clear clinical benefit from implantable pacemakers, part of patients is exposed to hazards associated with device implantation. One of the important issues among paced patients is pacemaker dependency, which is not an uncommon phenomenon and has a significant impact on the patient’s outcomes. The purpose of the present study is to evaluate the incidence of pacemaker dependency and to determine its probable predictors. Methods: This was a cross-sectional study among patients with permanent pacemaker implantation according to guideline-recommended indications, from March 2016 to March 2017 in Yazd province. During the interrogation of the device, an electrophysiologist recorded the percentage of ventricular pacing/all events according to stored data. Pacing dependency was categorized into three groups based on pacing percentage in the analysis (group 1: below 30%, group 2: between 30-70%, and group 3: above 70%). Results: A total number of 123 patients with permanent cardiac pacemakers were enrolled in our study. The mean duration between the device implant and follow-up visit was 37.4±34.4 months. The majority of patients were female (61.8%). The mean age of participants was 69.9±15 years. None of the clinical variables including age, gender, and body mass index predicted pacing dependency percentage (P-value: 0.64, 0.88, and 0.18 respectively). However, patients with dual-chamber pacemakers were more frequently pacedependent ( 70%) than single chamber pacemakers (86.8% versus 59.4 %, P-value: 0.001). Conclusion: Pacing dependency after the permanent pacemaker is much more common in our community. In addition, pacing dependency is associated with pacemaker type, which highlights the importance of device settings.