tof-plax1

This is a parasternal view (PLAX view) of tetralogy of Fallot. Note the large VSD. Note that the aorta is overriding the VSD. There is more than 50% aortic override. The same situation occurs in DORV also. To make the distinction, look for aortic-mitral continuity. In this case, there is aortic-mitral continuity. Thus, the diagnosis is TOF. If the aortic valve were more than 5mm away from the mitral valve, it would have meant that aortic-mitral continuity was absent and then the diagnosis would have been DORV.