269: Comparison of 2D and 3D transthoracic echocardiography for measurement of aortic annulus diameter in a paediatric population

Precise evaluation of the aortic root geometry is necessary in congenital aortic valve lesions in children, to optimize surgical or percutaneous procedures. The aim of the study was to compare two-dimensional (2D-TTE) and three-dimensional transthoracic echocardiography (3D-TTE) for analysis of aortic annulus and assess feasibility of 3D imaging.MethodsThirty consecutive children, without heart disease, aged 11± 3.6 years old (min 4; max 18; 66.7% boys), were prospectively included in this study. Transthoracic real time 2D and 3D echocardiography (ie 33, Philips, Andover MA, US) was performed using matrix probe (x 3-1, x 7-2 and x 5-1). Multiplanar reconstruction was used to measure in diastole two orthogonal aortic annulus diameters, compared to the measurement in a parasternal long axis view in 2D-TTE.Results3D aortic annulus diameters measurements were obtained in 28 (93.3%) children. Mean annulus diameter in 2D TTE (1.93±0.2cm) was not significantly different of the mean minimal diameter (1.95cm± 0.3, p=0.43) but was smaller than the mean maximal diameter (2.03cm ±0.3, p=0.002) in 3D-TTE. 2D annulus diameter was well correlated to minimal 3D diameter (r=0.89, p<0.0001) and maximal diameter (r=0.88, p<0.0001). A significant difference in the mean minimal and maximal 3D aortic annulus diameters was observed (p