The Heart Institute

Atrial Septal Defect (ASD)

An atrial septal defect (ASD) is a hole in the wall (septum) between the two upper collecting chambers of the heart. These holes may be of varying size and may be in any of several positions on the septum. The size of the defect and its location are factors which determine how serious the defect is with respect to the amount of strain on the heart and the degree to which blood crosses from one side of the heart to the other, causing a “flooding” of the lungs.

Patients with this lesion often have no symptoms, though they may have an increased incidence of lung problems. With time, however, the increased flow of blood to the lungs will cause irreversible damage.

The operation for ASD involves closing the hole, either by sewing its edges together or by placing a patch in the defect.

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