Quantitative Evaluation Of Left Ventricular Outflow Tract In Patients With S-shaped Ventricular Septum By Real-time Three-dimensional Echocardiography

Objective: Real-time three-dimensional echocardiography wasapplicated to evaluate left ventricular outflow tract of sigmoid ventricular septum(SVS)patinets quantitatively.Structural changes were discussed and measuring methods and data were compared between two-dimensional echocardiography(2DE)and three-dimensional echocardiography(3DE)to assess values of three-dimensional echocardiography in diagnosis of this diseases.Methods:57 cases of sigmoid ventricular septum and 18 healthy volunteers were included and divided into three groups: SVS obstruction type(39 cases),SVS non-obstruction type(18 cases)and healthy individuals(18cases).SVS obstruction type and SVS non-obstruction type were compared,SVS non-obstruction type and healthy individuals were compared.Three-dimensional echocardiography,full Volume image acquisition,Qlab9.1 offline analysis were used in two-dimensional measurement data including angle of the end-systole between ventricular septum and aortic root,left ventricular outflow tract width,left ventricular outflow tract velocity,ratio of room the upper and middle part of the interval,the aortic root and ventricular septum protruding end systolic distance measurement.Three dimensional measurement data included the volume of the left ventricular outflow tract,the minimum area of the left ventricular outflow tract,the ratio of the minimum area to the aortic root area,and the three-dimensional whole pattern of the left ventricular outflow tract.The distance between the root of the aorta and the protruding part of the upper part of the interventricular septum measured at the end-systole.Results: There was no significant difference in height,weight,systolic blood pressure and diastolic blood pressure in clinical data((p>0.05).For the data of 2DE,there was no significant difference between obstructive SVS patients and non obstructive SVS patients in the width of LVOT,19 ±2.4mm VS 17.8±2.2mm(p>0.05),besides there was no significant difference between obstructive SVS patients and non obstructive SVS in the angle ventricular septum and aortic root that obstructive SVS patients,102±11 VS 100±13(p>0.05).For the data of 3DE,the end systolic volume and the minimum end systolic area of SVS patients were significantly lower than that of normal adults,7.86cm3±2.37 VS 8.64cm3 ±1.60.(P<0.05),and 2.46±1.04cm3 VS 2.99±1.67cm3(P<0.05)respectively.The ratio of SVS patients with systolic left ventricular outflow tract of aortic root area and the minimum area was no significantly different than that in normal adults,1.75 ± 0.80 VS 1.14 ± 0.22,(P<O.05).The changed could be evaluated by 3DE with the three-dimensional morphology of LVOT,such as shapes of the circular shape,oval shaped and irregular shaped of the narrowest cross-sectional area of LVOT.Conclusion: Compared with 2DE,the volume,the structure change and the minimum cross-sectional area of LVOT could be evaluated by 3DE,having important advantages and significance for the assessment LVOT of SVS between patients with or without LVOTO.