Hi Greer, Welcome to the forum and hope you find a lot of support here. I am an ASD patient myself and will explain the role of blood thinners in my treatment so you can get an idea as your doctors “yes you could” clearly does not seem to be an adequate response to you at this stage.
After my ASD surgery I was given blood thinners (ecosporin) starting with a high mg which was gradually reduced by the cardiologist over the course of my follow up visits. I had to take ecosporin for 6 months post surgery and was only advised to stop it for a few days as I planned to undergo a dental procedure which did not happen.
My ASD was first discovered through a 2D ECHO, subsequent to which a TEE test was also conducted. Both tests give an indication of the presence of ASD but size is perhaps better understood from the TEE test.
To share a new learning from this forum, a new member just posted that s/he was diagnosed with ASD basis the 2DECHO but during the surgery it was discovered as a false positive. Moderators here will validate that this can happen. Hence, a request to do a TEE might be advisable before you resign yourself to have ASD.
Hope this helps.
All the best- Ashish