RESUMO
OBJECTIVE: To explore the effects of renal sympathetic denervation on inducibility of atrial fibrillation (AF) during rapid atrial pacing. METHODS: Thirteen dogs were selected and divided into control group (n=7) and renal artery ablation group (RAA) (n=6). In the control group, the animals were subjected to atrial pacing at 800 beats/min for 7 hours. And atrial effective refractory period (AERP) and induced AF were measured hourly during non-pacing. In the RAA group, after each renal artery ablation, the procedures of pacing and electrophysiological measurement were nearly the same as those in the control group. Blood was collected before and after pacing to measure the levels of rennin, angiotensin AngII (AngII) and aldosterone. RESULTS: There was a persistent decrease in AERP in both groups. However, after a 7-hour pacing, induced number of times and duration of AF were higher in the control group than those in the RAA group. The plasma concentrations of rennin and aldosterone increased significantly after 7-hour rapid pacing in the control group (rennin: (120±31) to (185±104) pg/ml, P<0.01, aldosterone: (288±43) to (370±110) pg/ml, P=0.01). No significant difference existed in the levels of AngII at pre- and post-pacing in the control group ((160±48) to (189±164) pg/ml, P=0.23). The levels of rennin and aldosterone showed a decreasing trend in the RAA group. But there was no statistical significance. CONCLUSIONS: Episodes of AF during short-time rapid atrial pacing may be decreased by renal sympathetic denervation. This effect is probably related with the decreased activity of RAAS.