LEFT VENTRICULAR REMODELING IN AORTIC INSUFFICIENCY

主动脉瓣关闭不全的左心室重构

• 批准号: 6091867
• 负责人: MICHAEL K PASQUE
• 金额: $ 27.1万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-10 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6091867
• 关键词: aortic valve; aortic valve insufficiency; biomechanics; cardiovascular surgery; clinical research; dobutamine; heart catheterization; heart contraction; heart ventricle; human subject; human therapy evaluation; longitudinal human study; magnetic resonance imaging; mathematical model; medical implant science; muscle stress; myocardium; pathologic process; postoperative state; preoperative state; prognosis; prosthetic heart valve

Introduction. Over the last nine years, our laboratory has helped develop and validate the mathematical modeling capabilities that are necessary to clinically evaluate the function of the heart by assessing the systolic and diastolic stress-strain relationships of the in vivo myocardium. This proposal would extend the application of these clinical tools to the comprehensive evaluation of the pathological left ventricular (LV) remodeling associated with severe aortic valvular insufficiency and the time course, degree, durability and prognostic significance of the reversal of this remodeling that occurs after aortic valve replacement (AVR). The accurate characterization of left ventricular remodeling and its reversal would have direct clinical relevance to a large number of clinically significant disease processes. Brief Study Overview. Magnetic resonance imaging (MRI)-based, 3D biventricular geometrical data-sets can be combined with biventricular loading conditions and finite element analysis to construct accurate, patient-specific systolic and diastolic mathematical (stress-strain) models of the heart. Patients with severe aortic insufficiency will undergo MRI scanning and catheterization prior to surgery to characterize the degree of left ventricular pathological remodeling that is present upon clinical presentation. 3D LV end-systolic stress (finite element analysis) and systolic strains (with and without Dobutamine stimulation) will be quantified and compared to post-operative data obtained at appropriate intervals. The change in LV end-systolic stress following surgery will reflect the interval change in geometry (reverse remodeling) that has occurred as a result of elimination of the aortic insufficiency by AVR. The time course, degree and durability of reversal of remodeling that occurs that AVR will be analyzed with respect to clinical outcomes. Preoperative characterization of diastolic material properties will also be related to subsequent postoperative reversal of remodeling and clinical outcomes.

导论.在过去的九年中，我们的实验室帮助开发和验证了数学建模能力，这是必要的临床评估心脏的功能，通过评估收缩和舒张期的应力-应变关系的体内心肌。该提案将扩展这些临床工具的应用，以全面评价与严重主动脉瓣关闭不全相关的病理性左心室（LV）重构以及主动脉瓣置换术（AVR）后发生的这种重构逆转的时间过程、程度、持久性和预后意义。左心室重构及其逆转的准确表征将与大量具有临床意义的疾病过程具有直接的临床相关性。简要研究概述。基于磁共振成像（MRI）的3D双心室几何数据集可以与双心室负荷条件和有限元分析相结合，以构建心脏的准确的、患者特定的收缩和舒张数学（应力-应变）模型。重度主动脉瓣关闭不全患者将在手术前接受MRI扫描和导管插入术，以表征临床表现时存在的左心室病理性重塑程度。将对3D LV收缩末期应力（有限元分析）和收缩期应变（有和无多巴酚丁胺刺激）进行量化，并与在适当时间间隔获得的术后数据进行比较。术后LV收缩末期应力的变化将反映由于AVR消除主动脉瓣关闭不全而发生的几何结构（逆向重构）的间期变化。将根据临床结局分析AVR发生的重构逆转的时间过程、程度和持久性。舒张期材料特性的术前表征也将与随后的重构和临床结局的术后逆转相关。