Cardiology Specialty Intern Cornell University Ithaca, NY, United States
Background: Although permanent pacemakers are routinely used to treat symptomatic bradyarrhythmias, long-term changes in interrogated and programmed parameters are not well characterized.
Objectives: The primary goal is to identify pacemaker parameters that significantly change over time. Secondary aims include comparing patient or pacemaker characteristics, such as body weight, generator brand, lead fixation type, etc., in relation to these changes and complications. Animals: Seventy-three client-owned dogs who received a pacemaker and had at least two subsequent interrogations were included.
Methods: Retrospective observational study. Patient characteristic and pacemaker parameters were documented. Timing of recheck interrogations were grouped for analysis in a linear mixed effects model (Table 1). Complications noted at each interrogation were recorded.
Results: Pulse width, battery life, and battery impedance significantly changed over time (Fig 1). Patients under seven years old had less battery life overall (P = 0.0014) as well as at multiple time points. Patients with endocardial leads with active fixation had a higher amplitude threshold (P = 0.0013), programmed amplitude (P = 0.0073), and sensitivity (P < 0.001), but there was no difference in the porportion of complications between types of fixation. Medtronic generators had more programming-related complications (P=0.0102) and required a numerically higher sensitivity (P=0.0018). Conclusions and clinical importance: Some pacemaker parameters changed over time, highlighting the necessity for evaluation of the individual patient. Certain patient or pacemaker characteristics may influence pacemaker function, with lead fixation type showing particular importance, but may not lead to more complications.
