Cardiovascular Flow Dynamics--in Vivo Imaging Studies

该项目强调使用新兴的强大的非侵入性超声成像技术来量化结构和功能性心血管病理学的研究。使用流体动力学原理，时间和空间方面的心脏结构异常和病理生理流事件的描述和量化验证。在心功能不全的临床治疗中，准确的定量评估对于诊断、预后和治疗具有重要意义。此外，非侵入性评估在经济上是可取的。为此，本年度的努力扩展了前几年的研究，包括：1）体内实验研究验证了新开发的动态3D数字彩色多普勒技术直接定量二尖瓣流量的可行性。2)实时3D超声心动图成像可以快速准确地测量左心室容积和质量。3)使用两个正交平面的平均值的数字彩色多普勒方法提供了准确的估计肺返流每搏输出量和返流分数，具有临床意义的连续量化术后法洛四联症患者的肺返流。4)连续波多普勒主动脉瓣返流频谱提供了一个可靠的无创估计左心室dP/dt，是潜在的帮助，在主动脉瓣返流患者的心室功能的系列评估。5)用于确定二尖瓣返流量的血流会聚表面的混叠距离与电磁流量探头确定的返流量之间观察到良好的相关性。6)在慢性动物模型中通过实时3D超声心动图定量主动脉瓣返流，计算为左心室和右心室每搏输出量之间的差异。这些研究报告已经出版或正在印刷中。正在进行的成像研究继续包括使用主动脉瓣和二尖瓣返流、急性和慢性心肌梗死和心室动脉瘤的慢性动物模型的研究。

This project emphasizes studies using newly emerging robust non invasive ultrasonic imaging technologies for quantifying structural and functional cardiovascular pathology. Using hydrodynamic principles, temporal and spatial aspects of cardiac structural abnormalities and pathophysiologic flow events are described and their quantification validated. In the clinical management of cardiac dysfunction, quantitatively accurate assessment is of major importance for diagnosis, prognosis and therapy. Non invasive assessment is, in addition, economically desirable. To these ends, the current year's efforts have extended previous years' studies to include: 1)An in vivo experimental study validated the feasibility of a newly developed dynamic 3D digital color Doppler technique for directly quantifying transmitral flow volume. 2) Real-time 3D echocardiographic imaging allowed rapid and accurate measurements of left ventricular volume and mass. 3) A digital color Doppler method using average values from two orthogonal planes provided accurate estimation of pulmonary regurgitant stroke volumes and regurgitant fractions, having clinical relevance for serially quantifying pulmonary regurgitation in patients with postoperative tetralogy of Fallot. 4)Continuous wave Doppler aortic regurgitant spectra provided a reliable noninvasive estimate of left ventricular dP/dt, being potentially helpful in the serial assessment of ventricular function in patients with aortic regurgitation. 5)Good correlation was observed between interaliasing distance of the flow convergence surface for determining mitral regurgitant volume and regurgitant volume determined by electromagnetic flow probes. 6)Quantification of aortic regurgitation by real-time 3D echocardiography in a chronic animal model was computed as the difference between left and right ventricular stroke volumes. These studies have been published or are in press. On-going imaging studies continue to include those using chronic animal models of aortic and mitral regurgitation, acute and chronic myocardial infarction and ventricular aneurysms.