This movie clip from a transthoracic echocardiogram shows the systolic left-to-right flow at the membranous ventricular septal defect (VSD) with color flow mapping (left hand frame). Color flow mapping also shows antegrade flow across the mitral valve (red) and the aortic valve (blue).
LV: left ventricle; LA: left atrium; RV: right ventricle; AO: aorta; arrow: VSD.