Computer Modeling and Cardiac MR of Structural Factors of Atrial Fibrillation

心房颤动结构因素的计算机建模和心脏磁共振

• 批准号: 8309358
• 负责人: Jason Ng
• 金额: $ 19.06万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8309358
• 关键词: Ablation; Aging; Algorithms; American; Anatomy; Area; Arrhythmia; Atrial Fibrillation; Atrial Flutter; Atrial Tachycardia; Cardiac; Clinical; Complex; Computer Simulation; Data; Detection; Development; Diagnosis; Dimensions; Effectiveness; Elderly; Electrophysiology (science); Failure; Fibrosis; Generations; Health; Heart Atrium; Heart Diseases; Image; Individual; Knowledge; Left; Left atrial structure; Left ventricular structure; Lesion; Magnetic Resonance Imaging; Maintenance; Modeling; Modification; Myocardial Infarction; Nature; Operative Surgical Procedures; Outcome; Pathway interactions; Patients; Persons; Play; Population; Procedures; Property; Protocols documentation; Pulmonary veins; Radiofrequency Interstitial Ablation; Recurrence; Relative (related person); Risk; Risk Factors; Role; Scanning; Series; Simulate; Structure; Testing; Time; United States; Work; X-Ray Computed Tomography; base; computer program; design; expectation; experience; follow-up; improved; insight; monolayer; novel strategies; programs; simulation; success; three-dimensional modeling; tool; user-friendly; virtual

DESCRIPTION (provided by applicant): Atrial fibrillation (AF) is an arrhythmia with complex and not well understood mechanisms which make treatment of AF a significant challenge. Multiple factors likely contribute to whether a person is susceptible to AF, including the existence of focal triggers, the complex anatomy of the left atrium, and the modification of atria substrate (e.g. fibrosis). Cardiac imaging, through MRI or CT, has been used to evaluate the three- dimension structure of the atria as guidance for radiofrequency ablation of AF. More recently, it has been shown that MRI can be used to detect fibrosis and ablation lesions in the atria. Despite these advances in atrial imaging, it is not clear how these data can be used to evaluate or treat of AF. We propose a novel approach to evaluate atrial geometry and substrate, as assessed by cardiac MRI, through computer simulations where realistic electrophysiologic properties are assigned to the three-dimensional geometry and by which "virtual" AF induction can be performed. The first aim of the project is to obtain the optimal parameters for obtaining high quality delayed-enhancement MRIs that will allow delineation of the atrial wall and detection of structural remodeling with reasonable scan times. In the second aim, a simulation tool will be developed to segment the atria and to apply a threshold-based algorithm to characterize each voxel of the atrial wall as being normal, structurally remodeled but viable, or structurally remodeled and non-viable. The tool will convert the three- dimensional voxel data into a monolayer polygon model on which computer simulations will be performed. A computer model that realistically simulates atrial electrophysiology will be used. The third aim will test the hypothesis that computer simulations incorporating MRIs taken prior to ablation and three months after ablation can be used to predict likelihood of success for ablation. The reason for the recurrence will be determined by comparing the computer simulations using the post-ablation MRI against the computer simulation using the pre-ablation MRI with the intended ablation plan. Incomplete ablation lesions or an inadequate ablation strategy may be implicated as reasons for the recurrence. This project represents a novel approach to study computer simulations of AF with MRI data from a large set of patients and is the first to test computer modeling as a potential clinical tool to evaluate AF patients. This study could have significant implications on the development of individualized strategies for radiofrequency ablation to treat AF.

说明(申请人提供)：房颤(房颤)是一种心律失常，具有复杂和不清楚的机制，使房颤的治疗成为一个巨大的挑战。一个人是否易患房颤可能有多种因素，包括局部触发因素的存在，左心房的复杂解剖，以及心房基质的改变(如纤维化)。心脏成像通过MRI或CT来评价心房的三维结构，作为射频消融房颤的指导。最近，有研究表明，MRI可以用来检测心房纤维化和消融性病变。尽管在心房成像方面取得了这些进展，但尚不清楚这些数据如何用于评估或治疗房颤。我们提出了一种新的方法，通过计算机模拟来评估心脏MRI评估的心房几何形状和底物，其中真实的电生理属性被分配给三维几何形状，并且可以通过该方法进行“虚拟”的房颤诱导。该项目的第一个目标是获得获得高质量延迟增强磁共振成像的最佳参数，以便以合理的扫描时间描绘心房壁并检测结构重构。在第二个目标中，将开发一个模拟工具来分割心房，并应用基于阈值的算法来表征房壁的每个体素是正常的、结构重构的但可行的，或者结构重构的和不可行的。该工具将把三维体素数据转换成单层多边形模型，在该模型上将进行计算机模拟。将使用逼真地模拟心房电生理学的计算机模型。第三个目标将检验这样一个假设，即包括消融前和消融后三个月的磁共振成像的计算机模拟可以用来预测消融成功的可能性。复发的原因将通过将使用消融后MRI的计算机模拟与使用具有预期消融计划的消融前MRI的计算机模拟进行比较来确定。不完全消融损伤或消融策略不当可能是复发的原因。该项目代表了一种利用大量患者的MRI数据来研究计算机模拟房颤的新方法，并首次测试了计算机建模作为评估房颤患者的潜在临床工具的可能性。这项研究对制定个体化射频消融治疗房颤的策略具有重要意义。