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.