Feasibility of AutoMVQ and comparison between TTE and TOE
There are a few studies in the literature which have included patients that were examined with TTE for MV analysis with promising results (20-22). In our study, we analyzed consecutive patients who were referred to our echo lab for TOE. All annulus and leaflet parameters were calculated in both TTE and TOE and statistical analysis demonstrated strong agreement between the two methods. 4D AutoMVQ analysis was more feasible and simpler with TOE rather than with TTE (96% vs 91%) due to clinical parameters that led to suboptimal TTE imaging, such as obesity, lung disease and inability for breath-hold for multi-beat acquisitions, or echocardiographic parameters that reduced the reproducibility of the method, such as irregular rhythm, extremely enlarged ventricles or atria and severe mitral annulus calcification.
Mitral annulus was larger in patients that were on AF, had MV pathologies (regurgitation or stenosis) or left ventricular and left atrial dilatation. Coronary artery disease did not affect the mitral annulus dimensions, except in case of ischemic cardiomyopathy and dilated LV. Patients with MR or mitral stenosis had increased dimensions of annulus but similar aorto-mitral angle, tenting height and tenting area. Tenting values were unaffected only in primary MR cases since in FMR tenting height is increased due to the tethering of the leaflets. The anterior mitral leaflet length was another variable that did not change along with the annulus enlargement. The presence of the trigonal fibrous tissue and the aorto-mitral continuity work as stabilizers for the anterior part of the valve. The posterior leaflet on the other hand is surrounded by the free wall of the atrium and ventricle which may explain the enlargement of the annulus towards this direction.