Hi ed34 --
Would atrial fibrillation be a reason for grade 2 diastolic dysfunction? If someone was in A Fib during the echo how would it affect the outcome? By the way, you always seem so knowledgeable on heart issues. Good to see you are still on here...I have noticed some of the "answerers" have gone...KenKeith specifically. Guess he "retired".
Well the first thing to do is get a diagnosis for the cause. If the left atrium is enlarged and you have diastolic dysfunction it is obvious what is going on, but you need to know 'why' before any decision can be made. What's going on is that the left ventricle isn't relaxing quickly enough, allowing the atrium to fully empty hence the forcing of enlargement. Your EF is likely normal because systolic function is often normal. There must be a reason it isn't relaxing properly though. More tests are required to determine that reason.