While surgery has been the standard treatment when the ASD is large, there are now investigational devices available to close some ASDs during a cardiac catheterization. There are three different forms of ASDs. The secundum defect is the most common form and generally occurs as an isolated defect. Surgical repair is usually straightforward. The primum ASD is associated with a cleft in the mitral valve which may also cause a leak in the valve.
Surgical repair involves patch closure of the ASD and often repair of the mitral valve.
Greater surgical expertise is required to repair this defect because of the proximity to the normal electrical system of the heart and the mitral valve abnormality. The sinus venosus defect is located in the superior portion of the atrial septum and is typically associated with abnormal drainage of the right upper pulmonary vein. Surgical repair involves closure of the ASD and redirection of the abnormal pulmonary vein back to the left atrium. ASD closure eliminates the excess blood flow which produced enlargement of the right side of the heart, and pulmonary hypertension in a small percentage of patients. ASD closure also eliminates the potential for paradoxical embolization, a situation in which a blood clot can enter the systemic circulation from the right side of the heart and produce a stroke or damage to other organ systems.