Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, California.
Department of Cardiovascular Surgery, David Geffen School of Medicine, University of California, Los Angeles, California.
J Surg Res. 2014 May 15;188(2):381-6. doi: 10.1016/j.jss.2014.01.016. Epub 2014 Jan 16.
The current commonly used cardiac ischemic preconditioning (IPC) protocol, involving three 5-min cycles of ischemia-reperfusion (I/R), may not be clinically beneficial because of its acutely deleterious effects on hemodynamics. This study attempted to assess the effects of a novel stepwise IPC scheme on cardiac function, infarct size, and arrhythmogenesis in a rabbit model of prolonged I/R.
Anesthetized open-chest rabbits were subjected to 60-min occlusion of a proximal branch of the left coronary artery followed by 180-min reperfusion. Animals were divided into five groups (n = 6 each): (1) control group (no IPC); (2) 2-min IPC group (three cycles of 2-min IPC); (3) 5-min IPC group (three cycles of 5-min IPC); (4) 10-min IPC group (three cycles of 10-min IPC); and (5) stepwise IPC group (2-, 5-, and 10-min I/R).
Compared with control group, 2-, 5-, and 10-min IPC decreased arrhythmia score by 16%, 67%, and 33%, respectively. Remarkably, stepwise IPC resulted in a 78% reduction of arrhythmias. Stepwise IPC also produced the least ventricular infarct size when compared with 2-, 5-, and 10-min IPC groups (16.4% versus 39.3%, 28.1%, and 38.5%, P < 0.05).
These results suggest that stepwise IPC has better cardioprotective effects against prolonged I/R injury and may serve as an acceptable approach to clinical revascularization procedures on the heart, including catheter-based and surgical approaches.
目前常用的心脏缺血预处理（IPC）方案，涉及三个 5 分钟的缺血再灌注（I/R）周期，可能由于其对血液动力学的急性有害影响而在临床上没有益处。本研究试图评估一种新的逐步 IPC 方案对兔长时间 I/R 模型中心功能、梗死面积和心律失常发生的影响。
麻醉开胸兔进行左冠状动脉近端分支 60 分钟闭塞，然后进行 180 分钟再灌注。动物分为五组（每组 n=6）：（1）对照组（无 IPC）；（2）2 分钟 IPC 组（3 个 2 分钟 IPC 周期）；（3）5 分钟 IPC 组（3 个 5 分钟 IPC 周期）；（4）10 分钟 IPC 组（3 个 10 分钟 IPC 周期）；（5）逐步 IPC 组（2、5 和 10 分钟 I/R）。
与对照组相比，2、5 和 10 分钟 IPC 分别使心律失常评分降低 16%、67%和 33%。值得注意的是，逐步 IPC 使心律失常减少了 78%。与 2、5 和 10 分钟 IPC 组相比，逐步 IPC 还产生了最小的心室梗死面积（16.4%比 39.3%、28.1%和 38.5%，P<0.05）。
这些结果表明，逐步 IPC 对长时间 I/R 损伤具有更好的心脏保护作用，可能成为心脏血管重建术包括基于导管和手术方法的可接受方法。
