To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Video 3 Large secundum atrial septal defect on 3D TOE visualized from the right atrial aspect. View Video 3 at http://movie-usa.glencoesoftware.com/video/10.1530/ERP-18-0074/video-3. Three-dimensional echocardiography in congenital heart disease John M Simpson, and Annemien van den Bosch 2019. 6:R75-R86 DOI: 10.1530/ERP-18-0074 Download Original Video