ABSTRACT
AIM:To evaluate the effects of atorvastatin (ATO) on atrial electrical remodeling in a rabbit mo-del of chronic atrial fibrillation (AF) produced by 3 weeks of rapid atrial pacing (RAP). METHODS:The sternotomy was performed and the pacing and testing electrodes were fixed to the left atria of 24 New Zealand white rabbits. The ani-mals were randomly divided into 3 groups. The rabbits in model group and ATO group were subjected to RAP for 3 weeks, and then were treated with placebo and ATO(2.5 mg·kg-1·d-1),respectively. The rabbits in sham group did not re-ceive RAP and drugs. Electrophysiological examination was performed to test heart rate, P-wave duration, atrial effective refractory period (AERP) and AF inducibility. The protein expression levels of Cav1.2, Kv4.3 and myeloperoxidase (MPO) were detected by Western blot. RESULTS:Sustained AF was induced in 5 and 4 rabbilts in model group and atorvastatin group and no rabbits in sham group was found. After 3 weeks of RAP, compared with sham group, heart rate and P-wave duration were increased and AERP was shortened in model group and ATO group(P<0.05). Compared with model group,AERP was increased in ATO group(P<0.05),while heart rate and P-wave duration had no difference be-tween these 2 groups. Compared with sham group, the protein levels of Cav1.2 and Kv4.3 were decreased, and protein level of MPO was increased in model group and ATO group (P<0.05). Compared with model group, Cav1.2 was in-creased and MPO was decreased in ATO group(P<0.05),while Kv4.3 had no difference between these 2 groups. CON-CLUSION:Atorvastatin suppresses the down-regulation of atrial Cav1.2 protein level and the shortening of AERP, thus preventing atrial electrical remodeling in a rabbit model of chronic AF. The effect of atrovastatin on reducing atrial MPO level may be the potential mechanism.