环孢素A对持续心房起搏犬心房电生理特性的影响

Effect of cyclosporine-A on electrophysiological properties of atria in the long-term rapid atrial tachypacing canine model

目的观察钙调神经磷酸酶抑制剂环孢素A(CsA)对慢性心房起搏犬电生理特性的影响。方法健康杂种犬18只,随机分为假手术组(Sham组,只手术不起搏)、快速起搏组(ATP组,植入固律型单腔起搏器,400次/分持续起搏8周)、CsA组(快速起搏基础上喂食环孢素A10mg.kg-1.d-18周),每组6只。实验前后进行电生理检测。记录并比较各组右房有效不应期(ERP)、传导速度(CV)、折返波长(WL)、心房颤动(简称房颤)负荷、频率自适应性等反映心房电生理特性的指标。结果快速起搏8周后ATP、CsA两组右房ERP值均较各组术前及假手术组明显缩短(P<0.05),但缩短程度CsA组显著小于ATP组(BCL300ms时,P<0.05)。两组频率自适应性,CV、房颤诱发率和持续时间无差异。结论环孢素A能够一定程度上抑制快速起搏导致的心房ERP的缩短,但并不因此改变房颤的诱发与维持。

Objective To investigate the effects of Cyelosporine-A （CsA）, an ealcineurin inhibitor, on eloctrophysiological properties of atria in the long-term rapid atrial pacing canine model. Methods Eighteen healthy adult mongrel dogs were equally divided into 3 groups randomly： （1）Sham group（ n = 6） ：pacemaker was implanted and there were no interventions. （2）ATP atrial tachypaeing group （n = 6 ） ： high-speed pacemaker was implanted and paced at a rate of 400 ppm. （3）CsA group （ n = 6） ： all cases undertook the same procedure as ATP group except that cyclosporine-A, 10 mg·kg^-1·d^-1 was added orally. A closed-chest EPS was performed on each group at baseline and after 8 weeks＇ rapid pacing. Resuits After 8 weeks＇ atrial rapid pacing, Compared to Sham group, ATP and CsA groups had a longer duration of the P wave （ P 〈 0.05 ）, shorter atrial effective refractory period （ERP） （ P 〈 0.05 ）, decreased adaptation of ERP （ P 〈 0.05 ）, slower conduction velocity （P 〈 0.05 ）, shorter wave length （P 〈 0.05 ）, longer AF duration. In comparison to ATP group, CsA group had a longer ERP （ P 〈 0.05 ） and a recovering tendency of other parameters but without statistical significance. Conclusions CsA has positive effect on tachycardia-induced atrial electrophysiological remodeling, but can not prevent or reverse AF.