My nurse said my results for my Thyroid Test were back and my AST was at 9? It should be around 10.30 she said , what does this mean?

I have mitro valve prolapse I have been told, but have been having more episodes with my heart beating spuratically and even stopping and starting again. I have been on several different medications, from propanolol, metoprolol tarta, now metoprolol succ er. The last seems to be helping with all my symptoms including regulating my high blood pressure. My Doctor started thinking that maybe this is all caused by my Thyroid since I am only going to be 37 this year. They did a blood work test for the Thyroid and it came back, they called me and want me to come in for a follow up , but cant get me in for 2 weeks, I asked about my test and she said that I was at a 9 on my AST , when I asked what that was and meant , she said she talked to the nurse and it was referencing to my liver, the nurse that a 10.30 was normal and I was at a 9? Im confused , and not gettin gany answers for 2 weeks can you help me as to defining this to me in lamens terms, thanks