Real-time three-dimensional echocardiography in diagnosis and quantitative assessment of congenital mitral regurgitation

Objective To evaluate the value of real-time three-dimensional echocardiography(RT3DE)in the diagnosis of children with congenital mitral regurgitation,and to establish new quantitative parameters for RT3DE mitral annulus,leaflets,papillary muscles,and left ventricle.Methods Twenty-four children with congenital mitral regurgitation(group 1)were recruited in this study and 24 healthy children(group 2)were studied as control.The morphology of the mitral valve was studied with transthoracic RT3DE image.Custom software(QLAB and self-designed Cadio 4D viewer)was used to trace the MV annulus,leaflets,the papillary apparatus,and left ventricular volume from the 3D data sets.Mitral valve annular area in end-systole(AA1)and annular area in end-diastole(AA2),the ratio of AA1 and AA2(T%),AL papillary muscle annular distance(AL-A),PM papillary muscle annular distance(PM-A),inter-papillary distance(AL-PM),the anterior leaflet and posterior leaflet tethering angles(a1,a2,argAL-C-PM),left ventricular volume of end-systole(LVESV),left ventricular volume of end-diastole(LVEDV),and left ventricular ejection fraction(LVEF)were measured.Results Morphologically,congenital clefts were detected with RT3DE.Three-dimensional parameters such as AA1,AA2,AL-A,PM-A,AL-PM,argAL-C-PM,LVEDV,and LVESV were significantly increased in group 1 than those in group 2,while parameter a1 and a2 were decreased significantly in group 1 than those in group 2.These changes revealed that factors such as clefts in the valve,activity of the abnormal valve,the size of the mitral valvular ring,location of the papillary muscle,and capacity of the left ventricle all affected normal opening and closing of the mitral valve.Conclusions RT3DE was useful in permitting comprehensive 3D viewing of the cleft in mitral regurgitation and three-dimensional parameters(AA1,AA2,argAL-C-PM,a1,a2,AL-A,PM-A,AL-PM,LVEDV,LVESV)were related to congenital mitral regurgitation in children.It demonstrates advantages in determining the mechanisms of congenital mitral regurgitation.