It will make it easier to understand the following defect. An ASD is an opening that exists between the heart's two upper chambers. This in turn leads to enlargement of the right atrium, and right ventricle.
More blood flows to the lungs as well.
Most children with ASD have few, if any, symptoms. It is somewhat dependent on size. In this case, the right ventricle is not enlarged, the pulmonary artery pressure is normal, and no problems should develop such as pulmonary vascular disease . The one complication of a small defect is that sometimes a right to left shunt can occur so that clots sometimes present in the veins going to the heart are not filtered by the lungs and go directly to the body. These traveling clots are known as emboli and can cause strokes.