The Changes And Significance Of Inflammatory And Oxidative Stress Markers In Dog Model Of Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinic. Recent preliminary evidence shows the important role of inflammation and oxidative stress in electrical and structural refractory of AF. Little research was report about the relationship between inflammation or oxidative stress with AF altogether. So there were many question in the mechanism of inflammation and oxidative stress in the trigger or maintain function of AF. In this study, we established a canine model of acute AF by rapid right atrial pacing and study the dynamic variation of the index of electrophysiology, inflammation and oxidative stress. By analyzing these results to investigate the possible relevance of inflammation and oxidative stress and the mechanism in AF.Objective: To investigate the mechanisms of pathogenesis of AF by analyzing dynamic changes of inflammatory and oxidative stress markers in a canine model of AF induced by rapid atrial pacing.Methods: Twenty-four canines were randomly divided into rapid artrial pacing (RAP) group and normal control(NC)group. In the RAP group the right atrium was paced at 800 bpm to induce and maintain AF for 2 hours; The atrial electrophysiological indexes (AERP, AFII), inflammatory markers (TNF-α, IL-6) and oxidative stress markers (XO, GSH-Px) in serum were measured at different time point(baseline, 1 h and 2 h after pacing,and 10 min, 20 min, 30 min after pacing ceased).Results:①The AERP shortened dramatically and AFII increased significantly after 1 hour pacing in RAP group (P<0.01);②after 1 hour pacing, in RAP group, the level of oxidative index (XO) increased (P <0.01), while the level of anti-oxidation index ( GSH-Px ) dropped (P <0.05) , the two indexes reached maximum and minimum respectively at 2 h. The levels of TNF-αand IL-6 had no significant changes at 1 h, but increased markedly after 2 hours pacing in RAP group; 3) At 1 and 2 h, the level of both XO and GSH significantly correlated with AF induced rate(XO: rT1= 0.74, P <0.01;rT2= 0.68, P <0.05; GSH: rT1= -0.78, P <0.01;r rT2= 0.83, P <0.01)). But a significant positive correlation could be found only after 2 h pacing between inflammatory markers (TNF-α, IL-6) and AF induced rate (r:0.67,0.71,P <0.05) . At 1 h and 2 h, AERP200ms significantly correlated with AF induced rate(r rT1= -0.69,P <0.05; r rT2= -0.81, P <0.01).Conclusion: Oxidative stress and inflammatory reaction are closely associated with AF and electrical remodeling. Oxidative stress markers could predict the genesis of AF.