EXTRACORPOREAL PERFUSION FOR ACUTE MYOCARDIAL INFARCTION

急性心肌梗死的体外灌注

• 批准号: 3351224
• 负责人: L HENRY EDMUNDS
• 金额: $ 28.22万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3351224
• 关键词: acute disease /disorder; disease /disorder model; dogs; epicardial mapping; extracorporeal circulation; heart contraction; intracardiac volume; muscle stress; myocardial infarct sizing; myocardial infarction; oxygen consumption; sheep

This proposal will test the hypothesis that temporary left ventricular assistance (LVAD) can accelerate recovery of left ventricular function by reducing left ventricular (LV) wall stresses, strains and myocardial creep and by accelerating recovery of the functional borderzone after acute myocardial infarction (AMI). These changes may accelerate LV remodeling, reduce final Ventricular volumes and preserve more contractile function after AMI in addition to preventing continuing myocardial ischemia and necrosis during evolution of infarcts in patients with multivessel disease. The project will utilize sonomicrometry to accurately measure LV dimensions throughout the cardiac cycle. The method developed to image LV geometry in 2 dimensions will be developed further to 3-dimensional mapping of LV geometry. This will allow estimations of regional LV wall stresses in pathologic infarcted ventricles based on direct measurements. The pathophysiology of reversible ischemia and LV distention (related to myocardial creep) will be investigated. The evolution of an apical myocardial infarct to apical LV aneurysm will be described in terms of LV mechanics and 02 consumption. These studies will be compared to evolution of circumflex coronary artery infarcts to scar and to the effects of LVAD on LV mechanics and 02 consumption at various time periods during evolution of both types of infarcts. The studies will focus on quantitation of - regional stresses, strains and creep in adjacent and remote myocardium after infarction and will assess changes in ventricular volumes and contractility with and without LVAD. The study will also determine the effects of changes in regional stresses and strains produced by LVAD or aneurysm plication (a model to acutely alter LV volume and regional stresses) on ventricular volumes, contractility and remodelling. Previous work compared several temporary extracorporeal circulatory assist systems that could be implemented without thoracotomy and determined that LVAD produces the most dramatic decreases in LV volumes and wall stresses in pathologic hearts. Therefore, the project seeks to understand the mechanisms involved in the recovery of LV function after AMI and to favorably influence this recovery by the use of LVAD without thoracotomy during the postinfarction period.

该提案将检验临时左心室的假设 辅助（LVAD）可以加速左心室功能的恢复， 减少左心室（LV）壁应力、应变和心肌蠕变 并通过加速急性后功能性边界区的恢复， 心肌梗死（AMI）。这些变化可能会加速LV重塑， 减少最终心室容积并保留更多收缩功能 除了防止持续的心肌缺血外， 在多支血管疾病患者的梗死进展过程中出现坏死。 该项目将利用超声测微法准确测量LV尺寸 在整个心动周期中。开发的左心室几何成像方法， 2维将进一步发展为LV的3维标测 几何这将允许估计局部LV壁应力， 基于直接测量的病理性梗死心室。 可逆性缺血和LV扩张的病理生理学（与 心肌蠕变）进行研究。顶端的进化 心肌梗死至心尖部LV动脉瘤将根据LV 机械和02消费。这些研究将被比作进化论 回旋支冠状动脉梗死的瘢痕和LVAD的影响 在进化过程中不同时间段的LV力学和O2消耗 两种类型的梗塞。这些研究将侧重于定量- 邻近和远端心肌的局部应力、应变和蠕变 并将评估心室容积的变化， 有和没有LVAD的收缩性。该研究还将确定 LVAD产生的局部应力和应变变化的影响，或 动脉瘤折叠术（急性改变LV体积和局部 应力）对心室容积、收缩性和重塑的影响。 以前的工作比较了几种临时体外循环辅助 可以在没有开胸手术的情况下实施的系统，并确定， LVAD使LV容积和室壁应力最显著降低 在病态的心脏中。因此，该项目旨在了解 AMI后左室功能恢复的机制， 在不开胸的情况下使用LVAD有利地影响这种恢复 在梗塞后时期。