ASD hole size is 7 mm with left to right shunt. Should I need surgery to correct heart defect?

Atrial Septal Defect (ASD) A hole in the wall (septum) that separates the two upper chambers (atria) of the heart. An atrial septal defect (ASD), or "hole in the heart," (It is often considered that the size of a larger defect ranges from 5 to 18 mm, and the smaller defect from 2 to 7 mm, with the distance between the borders of the communications ranging from 2 to 12 mm. This is only a rough estimate, when considering many such defects.) allows blood to flow from one atrium to the other, usually from the left side to the right side. This causes extra blood flow in the right atrium, in the right ventricle, and to the lungs. The size of an ASD can range from small to large..Most small defects close on their own as the heart grows during childhood. They usually allow only a small amount of blood to flow between the atria.Moderate to large defects are much less likely to close on their own. They allow two or more times the normal amount of blood to flow through the right side of the heart. Large holes sometimes cause symptoms during infancy or childhood. Half of all ASDs close without treatment. When treatment is necessary, it is usually successful. Once the defect has closed or has been repaired, most children: Don鈥檛 need additional treatment or medicine and can live normal, healthy lives. There is no single, known cause of atrial septal defect (ASD). Heredity (genetics) may play a role in ASD. In some cases, it may be due to a difference in one or more genes. Types of treatment include: Monitoring and observation (periodic checkups). Medicines. Closure of the ASD through surgery or a procedure using a catheter. Some adults have their ASDs closed to prevent or minimize symptoms and complications. After ASD closure, full recovery takes longer for adults than for children. You may benefit from a cardiac rehabilitation program as you recover from your ASD closure. Talk with your doctor about when it is all right for you to drive, return to work, resume exercising, and do other activities.
Hope this helps
Matador

The blood in the heart should not shunt between R/L sides. The heart changes dramatically after birth but sometimes this process is incomplete.

You (or your child?) obviously have some health issues to have had diagnostic testing.

In some individuals the problem(s) will correct with time, are non-problematic or need to be fixed. Only your cardiologist can make this determination.

My advice is to follow your MD's recommendations. If you have reservations then get a second opinion.

Good Luck :-)