摘要
目的:研究犬短QT综合征模型易发致命性心室颤动的电生理机制。方法:应用吡那地尔建立比格犬短QT综合征模型,利用篮状电极标测左室心内膜心肌电位。比较静脉推注吡那地尔(负荷剂量0.5 mg/kg,维持剂量每小时0.5 mg/kg)前后,QT间期、T波峰末间期(Tp-Te)、心肌细胞复极90%的动作电位(APD90)及激动恢复时间(ARI)、心室颤动周长(VF-CL)等参数的变化。结果:与基础状态相比,吡那地尔显著缩短窦性心律和300 ms起搏时的QT间期,分别为(264±17)ms对(240±15)ms,P<0.01;(247±7)ms对(229±10)ms,P<0.01。应用吡那地尔后,APD90、ARI和VF-CL均较基础值显著降低,分别为(175±11)ms对(164±11)ms,P<0.01;(156±11)ms对(147±10)ms,P<0.01;(104±9)ms对(95±7)ms,P<0.01。同时,Tp-Te间距较基础状态延长19%,即(35.8±3.4)ms对(44.1±1.4)ms,P<0.01。结论:不应期缩短和不应期心室跨壁离散度增加可能是吡那地尔诱导短QT综合征并发致命性室性心律失常的电生理基础。
Objective：To investigate the electrophysiologic mechanism of life-threatening ventricular fibrillation （VF） in canine with short QT syndrome （SQTs）.Methods：SQTs models were established by pinacidil,and a basket catheter including 64 electrodes was inserted into the left ventricle to map the action potential of endocardium.QT interval,action potential duration at 90％ repolarization （APD90）,activation recovery interval （ARI） and Tpeak-Tend（Tp-Te） interval were measured before and after intravenous administration of pinacidil （loading dosage at 0.5 mg/kg,maintenance dosage at 0.5 mg/kg per hour）.Results：Compared with baseline,pinacidil significantly shortened QT interval both at sinus rhythm and at the pacing cycle length of 300 ms,which were（264 ± 17）ms vs （240 ± 15） ms （P＜0.01） and （247 ± 7） ms vs （229 ± 10） ms （P＜0.01）,respectively.Pinacidil led to marked abbreviation of APD90,ARI and VF-CL,which were （175 ± 11） ms vs （164 ± 11） ms （P＜0.01）,（156 ±11） msvs （147±10） ms （P＜0.01） and （104±8） ms vs （94±7） ms （P＜0.01）.TpTe was significantly increased by 38％ after the drug administration,that was （35.8 ± 3.4） ms vs （44.1 ±1.4） ms （P＜0.01）.Conclusion：Abbreviated effective refractory and increased transmural dispersion of repolarization could be the possible electrophysiological basis of life-threatening ventricular arrhythmias in a canine model of SQTs established by pinacidil.
出处
《国际心血管病杂志》
2014年第1期55-57,共3页
International Journal of Cardiovascular Disease
基金
NSFC(81270260
81070266
81000081)
上海市教委高校创新团队发展计划
上海市科委(13140903702)
关键词
吡那地尔
短QT综合征
心室颤动
电生理学
Pinacidil
Short QT syndrome
Ventricular fibrillation
Electrophysiology
