远端器官预缺血改善冠状动脉缺血再灌注时心肌血供及减少心律失常发生率

远端器官缺血性预处理 (RPC)可减少缺血再灌注后心肌坏死范围。本研究旨在观察RPC对缺血再灌注心脏不同部位血流及心律失常发生率的影响。方法 :19头成年绵羊随机分为对照组 (n =9)及RPC组 (n =10 )。RPC组动物接受 3次左侧股动脉阻断 (5min)及再灌注 (5min) ,随后两组动物均分别依次阻断左冠状动脉前降支 (LAD) 10min ,再灌注 10min ;左冠状动脉第一分支 (D1)阻断及再灌注 10min后阻断左旋支 (LCX) 10min ,再灌注后观察 12 0min。结果 :LCX再灌注 10min时RPC组左室心内膜前壁、间隔及心外膜间隔心肌血流量 (分别为 0 .86± 0 .2 7,1.10±0 .34及 1.2 0± 0 .5 1ml·min-1·g-1)显著高于对照组 (分别为 0 .6 4± 0 .2 8,0 .6 9± 0 .2 3及 0 .5 8± 0 .2 6ml·min-1·g-1) ,P <0 .0 5。RPC显著减少再灌注后心室纤颤的发生率 (对照组 8/ 9,RPC组 2 / 10 ,P <0 .0 1)。冠状动脉阻断及再灌注后对照组主动脉平均压低于RPC组 ,但差异无显著性 (P >0 .0 5 )。结论 :RPC显著减少心肌缺血及再灌注期心室纤颤的发生 ,其机制可能与RPC显著改善心内膜血液供应有关。

Remote Preconditioning Improves Myocardial Blood Flow and Reduces Post-ischemic Arrhythmia After Consecutive Coronary Artery Occlusion and Reperfusion

Remote organ ischemic preconditioning (RPC) may reduce heart infarct size following myocardium ischemia and reperfusion.We aim to observe the effects of RPC on regional myocardial blood flow (MBF) and ischemic arrhythmia after consecutive coronary artery occlusion and reperfusion.19 adult sheep were randomly divided into control group (Group C, n =9) and remote preconditioning group (Group RPC, n =10).Animals in RPC group received 3 episodes of 5 min occlusion and 5 min reperfusion of the left iliac artery.After that,10 min occlusion followed by 10 min reperfusion of the left anterior descending (LAD),the first diagonal (D 1) and the left circumflex (LCX) coronary arteries were performed consecutively in all animals.MBF was measured with colored microspheres.Results:10 min after LCX reperfusion,MBF in the anterior and septal endocardium as well as in the septal epicardium of left ventricle in group RPC (0.86 ±0.27,1.10±0.34,and 1.20±0.51 ml·min -1 ·g -1 respectively) were significantly higher than the corresponding values in group C (0.64±0.28,0.69±0.23 and 0.58±0.26 ml·min -1 ·g -1 respectively) ( P <0.05).8 sheep in group C (8/9) and 2 sheep in group RPC (2/10) developed ventricular fibrillation after coronary reperfusion ( P <0.01,group C vs group RPC).Mean aortic blood pressure in group C was lower than that in group RPC during coronary occlusion and reperfusion,but the difference did not reach statistic significance ( P >0.05).Conclusion:RPC improves myocardial blood flow and reduces post ischemic arrhythmia after coronary artery occlusion and reperfusion,which may have potential clinical significance.