How big the atrial septal defect can be self-healing, mainly depends on the size of the atrial defect and the shape of the defect, such as atrial defect in children, because the atrial defect of 3mm-4mm in infants, which is equivalent to the case of having a cross, it is generally self-healing. If the atrial defect is larger compared to larger, more than 5mm, it may be relatively small, this kind is mostly seen like a matchstick, the possibility of self-healing of atrial defect in this case is smaller, it will become bigger and bigger, just like the leaves seen in autumn, like the sprout in spring, the insects bite a small hole, in autumn when the leaves are bigger, the same is true for atrial septal defect. The atrial septal defect may be small when it is small, 5mm-6mm, but when it grows up, it will be bigger, and in this case it will not grow, so whether it can grow or not depends not only on the atrial defect, but also on the ultrasound image to see whether it has crossover and overlap to determine whether it can heal itself.