氯沙坦对心房急性电重构的影响

Effects of lorsatan on acute atrial electrical remodeling

目的 以地尔硫为对照 ,探讨氯沙坦对心房快速起搏诱发急性电重构的干预作用。方法 2 1只兔随机分为盐水组、地尔硫组和氯沙坦组。 2F电极导管分别置于高位右心房 (HRA)、低位右心房 (LRA)和希氏束区 (HIS) ,以最快 1∶1起搏频率心房起搏 3h。阻断自主神经后 ,观察各组心房快速起搏前后 ,不同部位心房有效不应期 (AERP)、AERP频率适应性、AERP离散度 (AERPd)及右心房内传导时间变化。结果 (1)心房快速起搏后 ,盐水组AERP2 0 0 和AERP150 立即缩短 ;起搏 1h达最小值(P <0 0 5 ) ,起搏 0 5h内AERP2 0 0 和AERP150 缩短速率最快 [(30 2± 10 5 )ms/h ,(2 4 1± 9 1)ms/h];地尔硫组和氯沙坦组心房快速起搏后AERP无显著缩短。 (2 )心房快速起搏前 ,盐水组HRA处(AERP2 0 0 -AERP150 ) / 5 0ms为 0 17± 0 0 8,起搏 0 5、1、2、3h后分别为 0 0 8± 0 0 6、0 0 9± 0 0 6、0 0 8± 0 0 4、0 0 9± 0 0 5 ,P <0 0 5 ,提示AERP频率适应性降低 ;地尔硫组和氯沙坦组心房快速起搏前后 ,该值差异无显著性。 (3)盐水组心房快速起搏 2、3h ,AERPd明显增大 (P <0 0 5 )。地尔硫组心房快速起搏 3h ,与起搏前比较 ,AERPd显著增大 (P <0 0 5 )。氯沙坦组心房快速起搏后 ,AERPd无显著增加。

Objective To investigate the effects of lorsatan on tachycardia-induced acute atrial electrical remodeling(AER).Methods Twenty-one rabbits paced with maximal atrial capture rate for 3 h were randomly divided into saline group,diltiazem group and lorsatan group.Three 2 F electrode catheters were positioned in high right atrium(HRA),low right atrium(LRA) and His bundle region(HIS).After autonomic blockade,the pre-tachycardia,post-tachycardia atrial effective refractory period(AERP),AERP rate adapting feature,AERP dispersion(AERPd) and right-atrium conduction time were measured.Results (1) In the saline group,there was a prompt decrease in AERP as the result of rapid atrial pacing.AERP_ 200 and AERP_ 150 shortened most quickly within 0.5 h pacing [(30.2±10.5) ms/h,(24.1±9.1) ms/h]and most significantly at 1 h ( P <0.05).The AERP did not change dramatically in diltiazem and lorsatan groups;(2)In the saline group,the (AERP_ 200 -AERP_ 150 )/50 ms in HRA was 0.17±0.08 at 0 h and became significantly smaller at 0.5,1,2,3 h(0.08±0.06,0.09±0.06,0.08±0.04,0.09±0.05,respectively, P <0.05),suggesting a reduction of rate adaptation of AERP.It did not change during the 3 h of pacing in diltiazem and lorsatan groups;(3)In the saline group,AERPd increased significantly at 2,3 h( P <0.05).Diltiazem could not prevent the increase of AERPd at 3 h( P <0.05).During lorsatan infusion,the AERPd was no longer increased by rapid atrial pacing.There was no significant difference in right-atrium conduction time among the three groups.Conclusion Like calcium antagonist--diltiazem,lorsatan can prevent AERP shorteing induced by rapid atrial pacing.Lorsatan is more valuable than diltiazem in inhibiting the increase of AERPd.