【摘要】 目的 应用单相动作电位(MAP)技术，系统研究T波电击引起的复极离散(SIDR)与诱发心室颤动(VF)的关系。方法 截尾指数为65%/65%，脉宽5 ms的双相电流，以电击强度与配对间期的随机组合施加于稳态起搏的Langendorff离体灌流家兔心脏的舒张期。8个心外膜和2个心内膜位点同步记录MAP。SIDR定义为MAP同步记录中最长与最短电击后复极时间之差。结果 诱发VF的电击引起的SIDR为(64±15)ms，但当配对间期分别移出易损窗口左右沿各10 ms后，SIDR显著变小，其值分别为(33±14)ms和(27±8)ms(与诱发VF电击比，二者皆P<0.001)。当配对间期位于易损窗口内，但电击强度高于易损上限(ULV)时，SIDR显著变小，其值为(41±17)ms(与诱发VF的电击相比，P<0.01)。结论 VF的诱发与SIDR升高有关。

LI Cuilan,HU Dayi,Steffen Behrens,et al.Heart Center,Beijing Red Cross Chaoyang Hospital,Beijing 100020

【Abstract】 Objective Shock-induced dispersion of repolarization (SIDR) measured by multiple monophasic action potential (MAP) recordings and its relashingship to the induction of ventricular fibrillation (VF) by T wave shocks were studied. Methods Biphasic shocks (65/65% tilt,5 ms duration) were delivered to Langendorff-perfused rabbit hearts at shock coupling intervals (CI) ranging from 150～220 ms and shock strengths (SS) ranging from 140～540V.Ten MAPs were recorded simultaneously from 8 epicardial and 2 endocardial sites from both ventricles to assess SIDR at multiple sites.SIDR was defined as the difference between the longest and shortest shock-induced MAP response.Results VF induction was associated with high SIDR (64±15) ms.There was a significant decrease in SIDR as shock coupling intervals moved outside the borders of the vulnerable window (VW)[(33±14) ms left of the VW and (27±8) ms right of the VW,both P<0.001].For shocks within the VW,SIDR significantly decreased when SS reached values at or above the upper limit of vulnerability (ULV) [(41±17) ms, P<0.01]. Conclusion T wave shocks which induce VF are associated with a high degree of SIDR.

     ......