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: 8178902
• 负责人: Jason Ng
• 金额: $ 22.88万
• 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 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8178902
• 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. PUBLIC HEALTH RELEVANCE: Atrial fibrillation is rapidly emerging health issue in the United States, particularly among the elderly. Without the clear understanding of the mechanisms of atrial fibrillation, treatment options, such as radiofrequency ablation, remain suboptimal in terms of efficacy and risks.

描述（由申请人提供）：房颤（AF）是一种心律失常，其机制复杂且尚未充分了解，这使得AF的治疗成为一项重大挑战。多种因素可能会影响一个人是否容易患AF，包括局灶性触发因素的存在、左心房的复杂解剖结构以及心房基质的改变（例如纤维化）。通过MRI或CT进行的心脏成像已被用于评估心房的三维结构，作为AF射频消融的指导。最近，已显示MRI可用于检测心房中的纤维化和消融病变。尽管心房成像的这些进展，目前还不清楚这些数据可以用来评估或治疗AF。我们提出了一种新的方法来评估心房的几何形状和基板，心脏MRI评估，通过计算机模拟逼真的电生理特性被分配到三维几何形状和“虚拟”AF诱导可以执行。该项目的第一个目标是获得最佳参数，以获得高质量的延迟增强MRI，从而可以在合理的扫描时间内描绘心房壁并检测结构重构。在第二个目标中，将开发模拟工具来分割心房，并应用基于阈值的算法来将心房壁的每个体素表征为正常、结构重构但可行或结构重构但不可行。该工具将把三维体素数据转换成单层多边形模型，在该模型上进行计算机模拟。将使用真实模拟心房电生理学的计算机模型。第三个目标将测试假设，即计算机模拟结合消融术前和消融术后三个月的MRI，可用于预测消融术成功的可能性。将通过比较使用消融后MRI的计算机模拟与使用消融前MRI的计算机模拟以及预期消融计划来确定复发的原因。不完全消融损伤或消融策略不当可能是复发的原因。该项目代表了一种新的方法来研究AF的计算机模拟与MRI数据从一个大的病人集，是第一个测试计算机建模作为一个潜在的临床工具，以评估AF患者。这项研究可能对射频消融治疗房颤的个体化策略的发展具有重要意义。 公共卫生相关性：房颤是美国迅速出现的健康问题，特别是在老年人中。由于对房颤的机制没有明确的认识，射频消融等治疗方案在疗效和风险方面仍不理想。