Fig. 4

a and b Transthoracic echocardiography with color Doppler detected a severe pulmonic stenosis, with a peak velocity of 4.2 m/second. c Cardiac computed tomography image shows the pulmonic trunk overriding and straddling the ventricular septum. The anterior leaflet of the mitral valve is attached to the ventricular septum near the pulmonary valve. The mitral valve together with the outlet septum of the right ventricle caused the subvalvular pulmonary stenosis. The subaortic part is apparently stenotic in this view. d Cardiac computed tomography image also shows the subvalvular structure of the tricuspid valve connected to the ventricular septum. e A three-dimensional model of the cardiac computed tomography at a plane of (c) (as shown in E-1) shows detailed anatomy of the sub-pulmonary structure and its relation to the ventricular septum. f A three-dimensional model of the cardiac computed tomography at a plane similar to that in (d) (as shown in F-1) shows the widely open aorta outflow tract. The aortic outflow is separated from the stenotic pulmonary outflow tract by a prominent outlet septum. (Supplementary video is available in Additional files 3 and 4). AO aorta, A-OT aorta outflow tract, LA left atrium, LV left ventricle, MV mitral valve, OS outlet septum, PT pulmonic trunk, RA right atrium, RV right ventricle, TV tricuspid valve, VSD ventricular septum defect