i am sorry to hear that he and you will be in my prayers. i know how you feel , i have a dad who has a leaking heart valve which is leaking moderately
With LV aside, and if your son is clinically doing well and that the defect measures 3.4 mm, it can say that the defect is small. Therefore, it should not be causing him any significant problems. Of interest is the area of defect. If it is a muscular defect, then it should cause no problems. If it is a perimembranous defect, which is located beneath the aortic valve, it has the risk of deforming the aortic valve and causing it to prolapse and/or leak.
For some insight on defect closure. It can depend if there is any tissue covering the defect. Often, these defects are covered by excess tissue from the tricuspid valve.(right side valve). If there is no excess tissue covering the defect, then the likelihood that it will spontaneously close is low. If there is some tissue partially covering it, there is a somewhat better chance that, over time, it will close spontaneously. However, if it is not otherwise causing problems, it can be left alone without significant risk of harm.
Hope this helps give you a perspective. Take care and thanks for sharing.
is 3-4mm considered small or average?
Correction your son's doctor...not daughter!
Whether it is problematic depends on tne size and location, etc. Small VSDs don't cause problems and often may close on their own. Small VSDs don't cause any symptoms.
Medium VSDs are less likely to close on their own. They may require surgery to close and may cause symptoms during infancy and childhood.
A large VSD is less likely to close completely on its own, but it may get smaller over time. Large VSDs often cause symptoms in infants and children, and surgery usually is needed to close them.
Hope this information provides a perspective for you to further discuss the implications with your daughter's doctor. Take care and thanks for sharing.