Transthoracic echocardiography of a large secundum atrial septal defect in a six-year-old patient

(A) Subcostal two-dimensional echocardiographic view demonstrating a large secundum ASD (arrow).
(B) Same view with color Doppler flow imaging showing flow across the ASD (arrow). Red colored flow represents flow towards the transducer.
(C) Echocardiographic two-dimensional short axis view demonstrating the dilation of the RV in comparison with the LV.