Assessment of ventricular septal defects by real-time three-dimensional echocardiography and comparison with surgical measurements

Three-dimensional (3D) echocardiography has facilitated evaluation of a ventricular septal defect (VSD) with its true dimensions and exact localization and improved identification of various anatomical characteristics in different types of VSDs. We aimed at investigating the feasibility of 3D echocardiography in assessing VSDs in comparison to two-dimensional (2D) echocardiography. We employed both 2D and 3D echocardiography for measuring the longest diameter of VSD. The morphology, number, and size of the defect as well as its relation and distance to the tricuspid and aortic valves were analyzed by 3D echocardiography displaying the VSD from the right ventricular aspect. The size was defined in terms of maximum area, long and short axis diameters at end-diastole. The longest diameters of VSDs were compared with 2D and 3D echocardiography data in all patients as well as with the intra-operative findings in 17 patients. The mean diameters of end-diastolic VSDs measured by 3D echocardiography from the right ventricular aspect were significantly larger than those obtained by 2D echocardiography (15.6 ± 8.2 vs 10 ± 4.2 mm, P = .02), however, there was a good correlation between them (r = 0.73, P < .001). 3D echocardiography proved to be superior to 2D echocardiography for visualizing the shape of VSD and for measuring tissue rims from the aortic and tricuspid valves. The advantage was prominent in particular for viewing defects hidden by a ventricular septal aneurysm or a tricuspid septal leaflet, which can be erased digitally to reveal the VSD underneath. The dimensions of VSDs obtained by 3D echocardiography (r = 0.85, P < .001) correlated significantly better with actual dimensions revealed during surgery as compared to those obtained by 2D echocardiography (r = 0.53, P = .03). The study demonstrated that 3D echocardiography provides more reliable information from both qualitative and quantitative aspects regarding the morphology, size, and tissue rims of VSD compared to 2D views.