Validation of a Holographic Display for Quantification of Mitral Annular Dynamics by Three-Dimensional Echocardiography

Abstract

Background: Three-dimensional (3D) echocardiography with multiplanar reconstruction (MPR) is used clinically to quantify the mitral annulus. MPR images are, however, presented on a two-dimensional screen, calling into question their accuracy. An alternative to MPR is an autostereoscopic holographic display that enables indepth visualization of 3D echocardiographic data without the need for special glasses. The aim of this study was to validate an autostereoscopic display using sonomicrometry as a gold standard. Methods:In 11 anesthetized open-chest pigs, sonomicrometric crystals were placed along the mitral annulus and near the left ventricular apex. High-fidelity catheters measured left atrial and ventricular pressures. Adjustments of pre-and afterload were done by constriction of the inferior vena cava and the ascending aorta, respectively. Three-dimensional epicardial echocardiography was obtained from an apical view and converted to the autostereoscopic display. A 3D virtual semitransparent annular surface (VSAS) was generated to measure commissure width (CW), septal-lateral length, area of the mitral annular surface, nonplanarity angle, and the annular height-to-commissure width ratio in mid-systole and late diastole.Results: Mitral annular measurements from the 3D VSAS derived from the 3D echocardiographic images and autostereoscopic display correlated well with sonomicrometry over a range of loading conditions: CW length (r = 0.98, P < .00001), septal-lateral length (r = 0.98, P < .00001), annular surface area (r = 0.93, P < .001), nonplanarity angle (r = 0.87, P < .001), and annular height-to-commissure width ratio (r = 0.85, P < .01). The 3D VSAS showed better agreement with the sonomicrometric measurements compared with MPR.Conclusions: Mitral annular measurements using 3D VSAS correlate well with sonomicrometry over a range of loading conditions and may represent a powerful tool for noninvasive quantification of mitral annular dynamics. (J Am Soc Echocardiogr 2019;32:303-16.)

Assessment of mitral valve geometry in nonvalvular atrial fibrillation patients with or without ventricular dysfunction: insights from high volume rate three- dimensional transesophageal echocardiography

“…The non-planar saddle shape of the MA helps to maintain normal valve function by decreasing the blood ow pressure on the valves. [15,16] In a previous study, it was reported that NPA is better than AH/ALPMD at re ecting the attening of the MA because it is independent of changes in pre-and afterload heart. [15] In addition, the nadir point of AH is the midpoint of the mitral posterior annulus, and the nadir point of NPA is the midpoint of the ALPMD; which means these two parameters are not uniform, and there is only a weak correlation between NPA and AH/ALPMD.…”

“…[15,16] In a previous study, it was reported that NPA is better than AH/ALPMD at re ecting the attening of the MA because it is independent of changes in pre-and afterload heart. [15] In addition, the nadir point of AH is the midpoint of the mitral posterior annulus, and the nadir point of NPA is the midpoint of the ALPMD; which means these two parameters are not uniform, and there is only a weak correlation between NPA and AH/ALPMD. In our study, the increased NPA con rmed that the MA was attened in AF patients with LV dysfunction and in those without LV dysfunction.…”