In the moving clip from the subcostal parasagittal image window, the dynamic nature of the narrowing of the RVOT is highlighted by the superimposed color flow mapping. Systolic left-to-right flow from the VSD is also seen crossing the ventricular septum and entering the right ventricle caudal to the mid-chamber obstruction.
VSD: ventricular septal defect; PA: pulmonary artery; LVOT: left ventricular outflow tract; LA: left atrium; RV: right ventricle; IVS: intraventricular septum; thin arrow: VSD; RVOT: right ventricular outflow tract.