Influence of right ventricular pacing on mitochondrial function in adults.

Right ventricular pacing (RVP) frequency and duration significantly associate with RVP-induced cardiomyopathy. However, human data regarding RVP burden and mitochondrial function is scarce. We aimed to investigate the association between the duration and percentage of RVP and mitochondrial function in the peripheral blood mononuclear cells (PBMCs). This cross-sectional study enrolled individuals with a permanent pacemaker device with RVP capabilities, implanted for over 1 month, and exhibiting preserved left ventricular (LV) systolic function. The assessment of mitochondrial function was conducted using PBMCs to explore its correlation with RVP burden since pacemaker implantation. The analysis included 96 patients. The majority of patients had advanced or third-degree atrioventricular block, with a median RVP percentage of 84% and a median duration since implantation was 64 months. Substantial RVP percentage (RVP ≥ 40%) was independently associated with increased cellular oxidative stress (p = 0.015). Patients with longer RVP exposure (duration since implantation ≥ 60 months) were independently associated with increased mitochondrial oxidative stress (p = 0.030). Both associations remained significant after adjusting for confounding variables. In individuals with permanent pacemaker and preserved LV systolic function, substantial RVP percentage and prolonged RVP exposure were independently associated with increased cellular and mitochondrial oxidative stress.