ABSTRACT
Atrial septal defect (ASD) is the commonest form of congenital heart disease seen in adults. The commonest form of defect is the secundum ASD, accounting for two-thirds of cases, in which the fossa ovalis is absent, leaving a defect in the centre of the interatrial septum. Sinus venosus ASD is also rare and is found near to where the superior or inferior vena cava joins the right atrium. ASD can remain asymptomatic for many years and may present late in adult life. Percutaneous closure is performed for secundum ASDs if there is an adequate rim of tissue around the defect to allow deployment of a septal occluder device without impinging on nearby structures. Three-dimensional echo can be helpful in the assessment of congenital heart disease and has been of particular value in assessing ASDs, providing information on the morphology of the interatrial septum and the surrounding structures.
