THREE DIMENSIONAL VORTEX LIKE REENTRY IN CORONARY PERFUSED VENTRICULAR WALL

非梗死心肌的折返性室性心动过速 从根本上讲，这是一个三维类涡旋的传播问题 海浪。这项研究建议的目的是研究以下三个方面： 类涡旋再入的空间组织和时间演化 由开放的右室或左室过早刺激引起的 冠脉灌流的兔心肌壁。我们会 折返在心内膜和心外膜上的表现分析 表面使用光学映射技术来确定潜在的 活动的三维结构。我们也会研究这个角色 解剖因素，如心肌厚度的变化 冠状动脉壁、大血管和浦肯野纤维的存在 三维再入的起源和发展。此外， 研究脑室厚度的行为，我们将开发一种 一种点源和三维涡丝的定位方法 使用透照数据(前角)显示心肌壁 荧光)。我们的研究将基于以下假设：i) 变细丝涡旋波形式的涡旋状再入 I型、U型、L或O型等形状可由早熟引发 刺激；滚动波的特定形状可以通过以下方式控制 刺激电极的大小和几何形状，以及在 刺激的幅度和耦合间隔；ii)初始大小和 细丝的几何形状决定了涡旋的不同动力学- 在相同的准备中以不同的幅度观察到的再入 早熟刺激的耦合间隔III)三维涡旋 通常是不稳定的，它们的稳定是锚定到 宏观不连续。我们将使用一种电压敏感染料和一种 双视频成像系统，以及计算机建模来测试这些 假设。将使用两个摄像机来记录电波 从心内膜和心外膜表面同时传播 开放的右或左心室，并研究启动的机制， 涡旋波的动力学和终止。计算机模拟 三维传播将被用于开发刺激方案 它将用于启动光学测绘中的再入 实验；为了深入了解三维涡旋的机制- 如再入；分析结构性因素对稳定性和 三维再入动力学；并研究其表现形式 地面和透照中的各种形式的三维再入 光学测绘实验。拟议的工作预计将提供 关于三维空间之间关系的明确信息 孤立健康人的涡卷波折返性和室性心动过速 心。这样的信息应该有助于更好地理解 单形性室性心动过速和多形性室性心动过速的机制 将有助于地表和航向分辨率的解释 这种心律失常机制的壁内标测研究。整体而言 结果应该为差异的机制基础铺平道路 三维心肌中心律失常的诊断。归根结底，它是 希望从这些研究中获得的知识将适用于 人类折返性心律失常的认识和合理治疗。

Reentrant ventricular tachycardia in the non-infarcted myocardium is fundamentally a problem of propagation of three-dimensional vortex-like waves. The objective of this research proposal is to study the 3- dimensional organization and time evolution of vortex-like reentry initiated by premature stimulation in the open right or left ventricular wall of the coronary perfused rabbit ventricular myocardium. We will analyze the manifestation of reentry on the endocardial and epicardial surfaces using optical mapping techniques to determine the underlying three-dimensional structure of the activity. We will study also the role of anatomical factors such as variation in thickness of the myocardial wall, presence of large coronary vessels and presence of Purkinje fibers in the initiation and evolution of 3-dimensional reentry. In addition, to study the behavior in the thickness of the ventricles, we will develop a method for localizing point sources and 3-dimensional vortex filaments in the myocardial wall using transillumination data (front angle fluorescence). Our study will be based on the following hypotheses: i) vortex-like reentry in the form of scroll waves with varying-filament shapes, including I-, U-, L- or O-shapes, can be initiated by premature stimulation; the particular shape of the scroll wave may be controlled by the size and geometry of the stimulating electrode, as well as on the amplitude and coupling interval of the stimulus; ii) the initial size and geometry of the filament are responsible for varying dynamics of vortex- like reentry observed in the same preparations at various amplitudes and coupling intervals of the premature stimulus iii) 3-dimensional vortices are in general unstable, their stabilization being a result of anchoring to macroscopic discontinuities. We will use a voltage sensitive dye and a dual video imaging system, as well as computer modelling to test these hypotheses. Two video cameras will be used to record electrical wave propagation simultaneously from the endocardial and epicardial surfaces of the open right or left ventricle and to study the mechanisms of initiation, dynamics and termination of scroll waves. Computer modelling of propagation in 3-dimensions will be used to develop stimulation protocols which will be used for the initiation of reentry in the optical mapping experiments; to gain insight into the mechanisms of 3-dimensional vortex- like reentry; to analyze the role of structural factors on stability and dynamics of 3-dimensional reentry; and to study the manifestation of various forms of 3-dimensional reentry in surface and transillumination optical mapping experiments. The proposed work is expected to provide definite information regarding the relationship between 3-dimensional scroll wave reentry and ventricular tachycardia in the isolated healthy heart. Such information should lead to a better understanding of the mechanisms of monomorphic and polymorphic ventricular tachycardias, and will facilitate the interpretation of surface and course-resolution intramural mapping studies of such arrhythmia mechanisms. The overall results should pave the way to a mechanistic basis for the differential diagnoses of arrhythmia in the 3-dimensional myocardium. Ultimately, it is hoped that the knowledge derived from these studies will be applicable to the understanding and rational treatment of reentrant arrhythmias in man.