EXTRACORPOREAL PERFUSION FOR ACUTE MYOCARDIAL INFARCTION

这项提议将检验这样一种假设：临时体外循环 循环辅助(TECA)可加速左心功能恢复 功能，缩小梗死面积，从而通过减少 急性心肌梗死后的周向和局部心肌壁应力 心肌梗死(AMI)伴或不伴梗阻再通 冠状动脉。 离心泵灌流系统将被改装用于急性心肌梗死 开发外周、经皮插管、插管的技术 无开胸、搏动灌流和灌流的左心房 使用低剂量或不使用肝素。七种灌流系统组合，适合 在急性心肌梗死中使用，然后将评估他们减少左 收缩不良、戊巴比妥钠抑制状态下的室壁应力 羊心。左房-股动脉和静脉-动脉搭桥术 有无脉动流的连续和定时脉动流系统 将对主动脉内球囊反搏进行研究。一个系统，它 最大限度地减少左室壁压力，这是最实用的 用于急性心肌梗死，将被选择用于急性心肌梗死研究。 TECA促进血流灌注好、差的恢复的能力 收缩的室壁节段和缩小的梗塞面积将 在有回旋支冠状动脉闭塞的绵羊身上进行评估。 心肌节段性室壁缩短、室壁厚度与长短轴 除了主动脉流量和动脉直径外，还将用声波显微镜测量直径。 心腔压力。清醒的绵羊将被灌流96小时 选择了Teca系统，并与未灌流的对照动物进行了比较。 将对区域墙应力进行计算估计，并在 安乐死，将确定梗死区的大小。 可逆性和不可逆性脑缺血再灌注的影响 心肌节段性室壁运动，计算节段性室壁运动 压力和整体心功能，无论有没有TECA 在绵羊冠状动脉回旋支闭塞模型上测定。 获得的数据将定义Teca在急性心肌梗死中的角色(如果有)，并将 量化局部室壁运动的变化，计算估计 节段性室壁应力，以及无、早期、 以及闭塞冠状动脉的晚期再通。此信息 可能影响大型急性心肌梗死患者的现行管理 脑梗塞。

This proposal will test the hypothesis that temporary extracorporeal circulatory assistance (TECA) can accelerate recovery of left ventricular function, reduce infarct size, and thereby improve survival by reducing circumferential and regional myocardial wall stresses after acute myocardial infarction (AMI) with or without reperfusion of the obstructed coronary artery. Centrifugal pump perfusion systems will be modified for use in AMI by developing techniques for peripheral, percutaneous cannulation, cannulation of the left atrium without thoracotomy, pulsatile perfusion, and perfusion with low dose or no heparin. Seven perfusion system combinations, suitable for use in AMI, will then be evaluated for their ability to reduce left ventricular wall stress in poorly contractile, pentobarbital-suppressed sheep hearts. Left atrial-to-femoral artery and veno-arterial bypass systems with both continuous and timed pulsatile flow with and without intra-aortic balloon counterpulsation will be studied. One system, which maximally reduces left ventricular wall stress and which is most practical for use in AMI, will be chosen for AMI studies. The ability of TECA to accelerate recovery of well-perfused, poorly contractile ventricular segments and to reduce infarct size will be evaluated in sheep with occlusion of the circumflex coronary artery. Myocardial regional wall shortening, wall thickness and short and long axis diameters will be measured by sonomicrometry in addition to aortic flow and cardiac chamber pressures. Awake sheep will be perfused for 96 hours using the chosen TECA system and compared to unperfused control animals. Calculated estimates of regional wall stresses will be made, and after euthanasia, size of the infarcted area will be determined. The effects of reperfusion of reversibly and irreversibly ischemic myocardium on regional wall motion, calculated estimates of regional wall stress, and overall ventricular function with and without TECA will be determined in the sheep model of circumflex coronary artery occlusion. The data obtained will define the role, if any, of TECA in AMI and will quantitate changes in regional wall motion, calculated estimates of regional wall stress, and overall ventricular performance after no, early, and late reperfusion of an obstructed coronary artery. This information may influence current management of patients with large acute myocardial infarctions.