EXTRACORPOREAL PERFUSION FOR ACUTE MYOCARDIAL INFARCTION

急性心肌梗死的体外灌注

• 批准号: 3351226
• 负责人: L HENRY EDMUNDS
• 金额: $ 33.21万
• 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/3351226
• 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）可以通过以下方式加速左心室功能的恢复 减少左心室 (LV) 壁应力、应变和心肌蠕动 并通过在急性发作后加速功能性边界区的恢复 心肌梗塞（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 AMI 后除了预防持续性心肌缺血外， 多血管疾病患者梗塞演变过程中的坏死。 该项目将利用声测法精确测量 LV 尺寸 整个心动周期。开发用于对 LV 几何结构进行成像的方法 LV 的 2 维映射将进一步发展为 3 维映射 几何学。这将允许估计区域 LV 壁应力 基于直接测量的病理性梗塞心室。 可逆性缺血和左心室扩张的病理生理学（与 心肌蠕变）将被调查。顶端的演变 心肌梗塞至左心室心尖部动脉瘤将用 LV 来描述 机械和02消耗。这些研究将与进化论进行比较 冠状动脉旋支梗塞对疤痕和 LVAD 的影响 关于进化过程中各个时间段的 LV 机制和 02 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 梗塞后，将评估心室容量的变化和 有或没有 LVAD 时的收缩力。该研究还将确定 LVAD 产生的区域应力和应变变化的影响或 动脉瘤折叠术（一种急剧改变左心室体积和局部区域的模型） 应力）对心室容量、收缩性和重塑的影响。 之前的工作比较了几种临时体外循环辅助 无需开胸即可实施的系统，并确定 LVAD 使 LV 体积和壁应力显着降低 在病理性的心脏中。因此，该项目旨在了解 AMI 后左心室功能恢复的机制 通过使用 LVAD（无需开胸）对这种恢复产生有利影响 在梗塞后时期。