Mitral regurgitation (MR) is a valvular disease in which the mitral valve does not close properly, thereby allowing blood to flow backward from the left ventricle to the left atrium of the heart. MR is among the most prevalent valve problems in the Western world. Doppler echocardiography has recently emerged as the method of choice for the non-invasive detection and evaluation of MR severity. However, due to the various color Doppler limitations, the accurate quantification of MR remains one of the major challenges in modern echocardiography. This is particularly the case with eccentric, wall-hugging regurgitant jets, known as the Coanda effect. This form of MR is currently very difficult to quantify and may lead to gross under-estimation of regurgitant volume by inexperienced cardiovascular observers. Using mathematical modeling, bifurcation analysis, and numerical simulations, combined with the in vitro experimental modeling of MR, and clinical experience, the investigators are developing a state-of-the-art tool for accurate non-invasive assessment of mitral regurgitation. The mathematical approach utilizes the most recent advances in fluid-structure interaction, modeling the flow of an incompressible, viscous fluid, coupled with the motion of an elastic regurgitant orifice simulating the regurgitant valve. A bifurcation diagram providing the information about different types of MR is being developed. The in vitro model is based on a pulsatile flow loop incorporating a mock imaging chamber, which contains a regurgitant orifice simulating the flow conditions encountered in patients with MR.
This is an exciting, new study, addressing a significant problem in the development of non-invasive diagnostic tools for the quantification of valvular regurgitation. The interdisciplinary team of investigators is developing sophisticated novel mathematics, high performance computing, and in vitro experimental tools, which, when used together, provide novel information about the severity of mitral valve regurgitation, that could not be obtained by using each individual approach separately. Based on this collaborative endeavor, detailed information about the blood flow conditions in patient regurgitant valves will be obtained, that could not be obtained by using classical 2D or even 3D echocardiography. This information will be used to quantify the severity of MR, which is the fundamental data on which surgical interventions are decided. The complementary mathematical tools, combined with the echocardiographic images, and clinical experience, support the next step in the evolution of modern 3D echocardiography for non-invasive diagnosis of pathological complex intra-cardiac flows. The broader impacts will be achieved through student education via interdisciplinary training and interdisciplinary course preparation. Two of the investigators are women, and active recruitment of women and minorities will continue. This project contributes toward building a strong partnership between academia (University of Houston) and health/medical industry (The Methodist Hospital).
