中文摘要：

Objective To investigate the effects ofciyclosporine-A （CsA）,a calcineurin （CAN） inhibitor,on electrophysiological properties of atria in canine tachycardia-induced model of AF.Methods Eighteen healthy adult mongrel canines weighing 17.0 to 23.2 kg（ranged from 2 to 4 years old）were randomized to 3 groups,Sham group （no pacemaker was implanted）,atrial tachypacing group （ATP group） and CsA group (atrial tachypacing plus oral administration of CsA 10 mg·kg^-1·d^-1).Electrophysiological tests were performed on each group at baseline and after 8 weeks’ tachypacing.Measurements included atrial effective refractory period（AERP）,conduction velocity （CV）,wave length （WL）,atrial fibrillation load and rate-adaptability.Results After 8 weeks’ atrial tachypacing,ATP and CsA groups showed significant longer duration of the P wave,shorter AERP,decreased adaptation of AERP,slower CV,shorter WL and longer AF duration compared to the sham group （all P【0.05）.AERP of the CsA group was longer than that of ATP group （P【0.05）, but there were no differences in rate-adaptability,CV,incidence of induced AF and AF duration between CsA group and ATP group. Conclusions Our results suggest that calcineurin pathway intervention by CsA have a positive effect on tachycardia-induced electrical remodeling of atria,but can not prevent or reverse AF.

英文摘要：

Objective To investigate the effects of ciyelosporine-A(CsA).a calcinenrin(CAN)inhibitor,on electrophysiological propertiesof atria in canine tachycardia-induced model of AF.Methods Eighteen healthy adult mongrel canines weighing 17.0 to 23.2 kg(rangedfrom 2 to 4 years old)were randomized to 3 groups,Sham group(no pacemaker was implanted),atrial tachypacing group(ATP group)each group at baseline and after 8 weeks' tachypacing.Measurements included atrial effective refractory period(AERP),conductionvelocity(CV),wave length(WE),atrial fibrillation load and rate-adaptability. Results After 8 weeks' atrial tachypacing,ATP andCsA groups showed significant longer duration of the P wave,shorter AERP,decreased adaptation of AERE slower CV,shorter Wland longer AF duration compared to the shamg roup (all P＜0.05).AERP of the CsA group was longer than that of ATP group (P＜0.05),but there were no differences in rate-adaptability,CV,incidence of induced AF and AF duration between CsA group and ATP group.Conclusions Our results suggest that calcineurin pathway intervention by CsA have a positive effect on tachycardia-inducedelectrical remodeling of atria,but can not prevent or reverse AF.