无创肢体缺血预处理对兔缺血心肌电稳定性的影响及机制研究

目的：探讨无创肢体缺血预处理对兔缺血心肌电稳定性的影响及其电生理机制。方法：取家兔27只，随机分为：单纯缺血对照组（Ctr），无创肢体缺血预处理组（LIP），LIP＋KATP抑制剂格列苯脲组（LG），LIP＋p38MAPK抑制剂SB203580组（LSB），闭胸状态下同步记录体表ECG及心内外膜MAP，分析心肌缺血背景下MAPA、APD90、Vmax和，小律失常的类型、发生率及持续时间的变化。结果：缺血后，四组的平均心率、MAPA、Vmax均不同程度地减小，APD90不同程度地延长；LIP能抑制心律失常的发生，使心律失常持续时间缩短，LG组使心律失常发生降低，持续时间缩短，LSB组结果与对照组相近。结论：无创肢体缺血预处理具有增强兔缺血心肌电稳定性的作用，p38MAPK是其发挥保护作用的重要途径，而KATP则可能未参与其中。

PRECONDITIONING ON ELECTRICAL STABILITY OF ISCHEMIC MYOCARDIUM IN RABBITS AND ITS MECHANISM

Objective：To investigate the effect of non-invasive limb ischemic preconditioning on electrical stability of ischemic myocardium in rabbits. Methods：Twenty-seven rabbits were randomly divided into four groups： control （Ctr）,non-invasive limb isehemic preconditioning （LIP）,LIP ＋ KATP inhibitor glibenclamide （LG）, and LIP ＋ p38MAPK inhibitor SB203580 （LSB）. ECG , the endocardium and epicardium MAP Were simultaneously recorded in the state of closedthorax;changes in type, incidence and duration of arrhythmia, MAPA, APD90 and Vmax were analyzed before and after myocardium ischemic. Results：In Four groups after ischemia, the average heart rate, MAPA and Vmax were reduced APD90 extended in various degrees; non-invasive limb ischemic preconditioning could inhibit the rate of occurrence, and shorten the duration of arrhythmia;LG group could reduce the rate of occurrence and duration of arrhythmia;LSB group is similar to control group.Conclusion：Noninvasive limb ischemic preconditioning could enhance stability, p38MAPK may play an important role.