Abstract 9899: Effect of Renal Sympathetic Denervation on Atrial Fibrillation
Introduction- The fundamental mechanisms underlying atrial fibrillation (AF) have not been elucidated. Much attention has been devoted to assess the role of renin-angiotensin-aldosterone system (RAAS) in AF.
Hypothesis- We assessed the hypothesis that renal sympathetic denervation had effect on atrial substrate remodeling and inhibited inducilibity of AF by preventing RAAS.
Methods- Thirteen dogs were randomly divided into control group (7 dogs) and renal artery ablation (RAA) group (6 dogs). In control group, at first, AF was induced by anterior right ganglionated plexi (ARGP) stimulation. Then, rapid atrial pacing was performed for 7 hours and atrial effective refractory period (AERP) was measured. Subsequently, pacing was stopped and AF was induced again by atrial burst pacing. In RAA group, dogs were raised for 6 weeks after each renal artery ablation. After that, the procedure of pacing and electrophysiological measurement was nearly same as in the control group. Densities of autonomic nerve, Cx43 and ANP in pulmonary veins (PVs) and atrial tissues were measured and levels of TGF-β, Ang II and aldosterone in blood were studied.
Results- There was a persistent decrease in AERP in both the two groups. The voltage in the sinus rate slowing response and the threshold for AF inducilibity increased during ARGP stimulation after renal sympathetic denervation (3.5±1.6V vs 1.6±0.3V, P=0.03; 5.1V±1.0V vs 2.1V±0.7V, P=0.03). Induced number of times and duration of AF was higher in control group than that in RAA group after rapid pacing. The plasma Ang II and aldosterone concentration increased in control group while decreased in RAA group after rapid pacing. Furthermore, levels of ANP in right atrium and densities of Cx43 in PVs were lower in RAA group than that in control group (ANP: 220.5±37.6 pg/ml vs 164.4±22.0 pg/ml, P=0.02; Cx43: 1.91 vs 0.92, P[[Unable to Display Character: ]]0.01). There was no significant difference in the densities of autonomic nerve and TGF-β between the two groups.
Conclusions[[Unable to Display Character: ]]Renal sympathetic denervation results in atrial substrate remodeling and markedly decrease the inducilibity of AF by inhibiting activity of RAA.
- © 2012 by American Heart Association, Inc.