Characterization and synchronization of intraventricular filling vortices in the

心室内充盈涡流的表征和同步

• 批准号: 8096140
• 负责人: ANDREW KAHN
• 金额: $ 22.95万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-15 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8096140
• 关键词: Address; Affect; Apical; Biochemical; Blood; Blood flow; Cardiac; Cardiology; Clinical; Color; Coupled; Dependence; Diastole; Doppler velocimetry; Early Diagnosis; Echocardiography; Echocardiography, Doppler, Color; Engineering; Event; Evolution; Functional disorder; Generations; Goals; Heart; Heart failure; Human; Image; Intraventricular; Knowledge; Lead; Left; Left ventricular structure; Liquid substance; Magnetic Resonance Imaging; Maps; Measurement; Measures; Mechanics; Medical center; Methods; Modality; Myocardial; Myocardium; Outcome Study; Patient Selection; Patients; Pattern; Phase; Positioning Attribute; Process; Property; Protocols documentation; Research; Research Personnel; Role; Syndrome; Technology; Testing; Time; Ventricular; Ventricular Function; aortic valve; base; event cycle; hemodynamics; image processing; improved; indexing; insight; interest; novel; treatment strategy; two-dimensional; vector

DESCRIPTION (provided by applicant): Blood flow generation by the heart is the result of synchronized electromechanical myocardial events and fluid dynamics processes. Interactions between blood flow and the myocardium elicit the continuous remodeling of the heart, leading to flow patterns that minimize energy losses. The flow pattern in the normal left ventricle consists of a large diastolic vortex that channels the transit of blood towards the outflow tract. In a failing left ventricle, progressive adverse remodeling leads to abnormal flow patterns that are less efficient in channeling blood transit, and which may contribute further to the progression of heart failure. Thus, a deeper understanding of blood flow dynamics in normal and diseased left ventricles may provide insight on the pathophysiology of heart failure, leading to earlier diagnosis and improved treatment strategies of this syndrome. Recent years have witnessed a surge of interest in studying the role of flow patterns in blood transport inside the left ventricle. Despite significant advances, we still understand poorly how the fluid dynamical processes are synchronized with the electromechanical events to generate blood flow. Our preliminary studies suggest that the position and properties of diastolic vortices, and consequently, their ability to channel blood transit through the LV, are related to the timing of the myocardial events of the cycle. The goal of this research is to understand the dependence of the time evolution of the diastolic vortices on the duration of the left-ventricular filling phases, and to determine how this dependence affects blood flow transport and global ventricular function. In order to carry out the proposed research we have assembled an interdisciplinary team of investigators with complementary expertise ranging from cardiology, echocardiography and magnetic resonance imaging, to fluid dynamics, computational mechanics and image processing. We will validate and apply a novel echocardiographic modality to measure two-dimensional bi-directional time-resolved flow maps in the left ventricle in a group of patients undergoing cardiac resynchronization therapy at the UCSD Medical Center. We will use these measurements to determine the time evolution of diastolic vortices in these patients for different AV and VV delays, and characterize how these delays affect the transit of blood inside the left ventricle. We postulate that better knowledge of this dependence will increase our understanding of the benefits of cardiac resynchronization therapy. It will also improve current protocols for VV and AV optimization by improving patient selection and enabling LV contraction to take place under the most favorable hemodynamic conditions. PUBLIC HEALTH RELEVANCE: The proposed study aims to develop engineering technologies to non-invasively measure blood transport inside the left ventricle of patients undergoing cardiac resynchronization therapy, with the overarching goal of improving patient selection and optimization of this therapy.

描述（由申请人提供）：心脏产生的血流是同步机电心肌事件和流体动力学过程的结果。血流和心肌之间的相互作用引起心脏的持续重塑，从而形成最大限度地减少能量损失的流动模式。正常左心室的血流模式由一个大的舒张期涡流组成，该涡流引导血液流向流出道。在衰竭的左心室中，进行性不良重塑会导致血流模式异常，从而导致血液转运效率较低，并可能进一步导致心力衰竭的进展。因此，更深入地了解正常和患病左心室的血流动力学可能有助于深入了解心力衰竭的病理生理学，从而导致该综合征的早期诊断和改进的治疗策略。近年来，人们对研究左心室内血液输送中的血流模式的作用的兴趣激增。尽管取得了重大进展，但我们仍然对流体动力学过程如何与机电事件同步以产生血流了解甚少。我们的初步研究表明，舒张期涡流的位置和特性，以及它们引导血液通过左心室的能力，与周期中心肌事件的时间有关。本研究的目的是了解舒张期涡流的时间演变对左心室充盈阶段持续时间的依赖性，并确定这种依赖性如何影响血流输送和整体心室功能。为了开展拟议的研究，我们组建了一个跨学科研究团队，其专业知识互补，涵盖心脏病学、超声心动图和磁共振成像、流体动力学、计算力学和图像处理等领域。我们将验证并应用一种新型超声心动图模式来测量在加州大学圣地亚哥分校医学中心接受心脏再同步治疗的一组患者左心室的二维双向时间分辨血流图。我们将使用这些测量值来确定这些患者在不同 AV 和 VV 延迟情况下舒张期涡流的时间演变，并描述这些延迟如何影响左心室内血液的输送。我们假设，更好地了解这种依赖性将增加我们对心脏再同步治疗益处的理解。它还将通过改善患者选择并使左心室收缩在最有利的血流动力学条件下发生来改进当前的 VV 和 AV 优化方案。 公共健康相关性：拟议的研究旨在开发工程技术，以非侵入性测量接受心脏再同步治疗的患者左心室内的血液输送，总体目标是改善患者选择和优化该治疗。