Assessment of Left Ventricle Function Using Color M-Mode Echocardiography

描述（由申请人提供）：我们假设已知患有心功能不全的患者组（即，EF >0.50的HF、EF <0.40的HF和LV肥大）。这些改变表现为初始Vp的减小和从二尖瓣到减速发生点的距离的减小。充盈波的减速和LV内逆压梯度的开始之间的关系建立了控制充盈的物理机制。此外，我们假设一个新的参数，早期充盈强度（Vs），结合了初始Vp和减速距离，更好地将这些患者组与正常人相比，传统的舒张功能的措施（即VP，e，E/e，或等体积应变率）。我们的初步工作证明了我们的建议的可行性，我们的初步观察与我们的假设是一致的。我们将通过追求以下特定目标来探索上述假设：1）自动化CMM分析，以客观评估舒张充盈并消除操作员间的变异性。在我们的初步工作中，我们已经通过使用半自动算法分析单次心跳完成了这一点。我们现在将扩展此方法以自动评估多个心跳的数据，从而提高分析的易用性和准确性。2)开发一种基于物理学的方法，通过测量血流传播速度及其时间变化来表征舒张充盈，并根据临床获得的CMM超声心动图评估心室内压差。3)在一项前瞻性研究中评估舒张早期血流传播速度和心室内压差，该研究将包括EF保留和降低的健康患者和患病患者，使我们能够检验我们关于正常和异常舒张早期LV充盈的物理基础的假设，并与舒张功能的常规测量（即Vp、e '、E/e'、等容应变率）进行比较。

DESCRIPTION (provided by applicant): We hypothesize that LV filling dynamics are altered in patient groups known to have cardiac dysfunction (ie. HF with EF >0.50, HF with EF <0.40, and LV hypertrophy) compared to normals. These alterations are manifested by a reduction of the initial Vp and reduction of the distance from the mitral valve to the point where the deceleration occurs. The relationship between the deceleration of the filling wave and the onset of the adverse pressure gradient within the LV establishes the physical mechanism governing the filling. In addition we hypothesize that a novel parameter, the early filling strength (Vs), that combines the initial Vp and the deceleration distance, better separates these patient groups from normals compared to conventional measures of diastolic function (i.e. VP, e , E/e , or iso-volumetric strain rate). Our preliminary work demonstrates the feasibility of our proposal, and our initial observations are consistent with our hypotheses. We will explore the above hypothesis by pursuing the following specific aims: 1) Automate the CMM analysis to objectively assess diastolic filling and eliminate inter-operator variability. In our preliminary work we have accomplished this by using a semi-automated algorithm analyzing single heartbeats. We will now extend this method to automatically assess data from multiple beats, improving the ease of use and accuracy of the analysis. 2) Develop a physics-based method for characterizing diastolic filling by measuring the velocity of flow propagation and its temporal variations and assessing the intraventricular pressure gradients from clinically obtained CMM echocardiograms. 3) Assess early diastolic flow propagation velocities and intraventricular pressure gradients in a prospective study that will include healthy patients and diseased patients both with preserved and reduced EF, allowing us to test our hypothesis regarding the physical basis for normal and abnormal early diastolic LV filling and compare to conventional measures of diastolic function (i.e. Vp, e', E/e', isovolumetric strain rate).