A Study of Functional Anatomy of Aortic-Mitral Valve Coupling Using 3D Matrix Transesophageal Echocardiography

Abstract

Background— Mitral and aortic valves are known to be coupled via fibrous tissue connecting the two annuli. Previous studies evaluating this coupling have been limited to experimental animals using invasive techniques. The new matrix array transesophageal transducer provides high-resolution real-time 3D images of both valves simultaneously. We sought to develop and test a technique for quantitative assessment of mitral and aortic valve dynamics and coupling. Methods and Results— Matrix array transesophageal (Philips iE33) imaging was performed in 24 patients with normal valves who underwent clinically indicated transesophageal echocardiography. Custom software was used to detect and track the mitral and aortic annuli in 3D space throughout the cardiac cycle, allowing automated measurement of changes in mitral and aortic valve morphology. Mitral annulus surface area and aortic annulus projected area changed reciprocally over time. Mitral annulus surface area was 8.0�2.1 cm 2 at end-diastole and decreased to 7.7�2.1 cm 2 in systole, reaching its maximum (10.0�2.2 cm 2 ) at mitral valve opening. Aortic annulus projected area was 4.1�1.2 cm 2 at end-diastole, then increased during isovolumic contraction reaching its maximum (4.8�1.3 cm 2 ) in the first third of systole and its minimum (3.6�1.0 cm 2 ) during isovolumic relaxation. The angle between the mitral and aortic annuli was maximum (136�13�) at end-diastole and decreased to its minimum value (129�11�) during systole. Conclusions— This is the first study to report quantitative 3D assessment of the mitral and aortic valve dynamics from matrix array transesophageal images and describe the mitral-aortic coupling in a beating human heart. This ability may have impact on patient evaluation for valvular surgical interventions and prosthesis design.

Comparative numerical study on left ventricular fluid dynamics after dilated cardiomyopathy

“…Values of the orifice areas are reported in Table 1, which may differ from sizes based on the annulus edges that contain the valvular effective opening. The mean (heartbeat averaged) value of the angle between the mitral and the aortic orifice resulted in 1257 291 and 1357 341 for the healthy and DCM patients, respectively (Veronesi et al, 2009). With this in mind, the work presented herein is aimed as a simple integration with clinical imaging, using geometries derived from 3D reconstruction of the LV without further manipulation other than the congruence of the orifice size.…”

Personalized Modeling and Assessment of the Aortic-Mitral Coupling from 4D TEE and CT

“…Table 2 distance were 137.0±12.2 and 26.5±4.2, respectively compared to 136.2±12.6 and 25.0±3.2 reported in the literature [3]. Automatic, model-based quantification has the potential to advance patient evaluation, intervention planning and guidance.…”

“…The valves are coupled by a fibrous tissue [1] and work in synchrony [3,2] to regulate the blood flow in the left heart. The central anatomical structures are: aortic root and leaflets along with mitral anterior and posterior leaflets.…”

“…Reciprocal changes of the aortic and mitral annular areas have been reported and it was concluded, that the fibrous aortic-mitral continuity acts as an anchor for the valves. Together with the muscular portions of either annuli and their contraction during their reciprocal motion, it facilitates the opening and closing of the other valve during systole and diastole respectively [3]. Various findings and facts related to interventions on both valves emphasize the notion of their coupling.…”

“…To date, separate approaches were reported for modeling of both valves [6,7]. Veronesi et al [3] reported a method, where both annuli were segmented with manual initialization and quantified. Up to now the full joint morphology and dynamics of both valves at the same time have not been studied due to the lack of suitable methods and tools.…”