Atrial Septal Defect (ASD)

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A hole in the wall between the two upper chambers is called an atrial septal defect, or ASD. This is one of the least complex forms of congenital heart defect. There are three different kinds of ASDs. The most common form of ASD is the secundum defect which usually occurs as an isolated defect. The primum ASD is associated with a cleft in the mitral valve which may also cause the valve to leak. The third kind of ASD is the sinus venosus defect, located in the superior portion of the atrial septum and typically associated with abnormal drainage of the right upper pulmonary vein.

Atrial septal defects can vary greatly in size. Some ASDs will close on their own and no surgery is needed. Left untreated for decades, potential problems include lung disease, exercise intolerance, heart rhythm abnormalities, shortened life expectancy and the increased risk of a stroke.

Some ASDs are closed in the catheterization lab and do not require open-heart surgery. Certain devices such as the Amplatzer Occluder or Helex device are currently being used. Typically these devices are used only for the secundum ASD’s. The following illustration shows the location of an ASD.

Surgical Correction:  Some ASDs will need to be corrected with open heart surgery to restore normal blood circulation. The smaller ASD’s can be primarily closed with just suturing the opening. The larger ASD’s require a patch to partition the left and right chambers of the heart.  This partition is usually done with a piece of the child’s own pericardium, a thin sack of tissue that naturally surrounds the heart. The Ostium Primum ASD (partial AV Canal) is typically repaired by patching the “hole” with pericardium and repairing the cleft in the mitral valve. In the illustration below the ASD has been surgically corrected.