This should be a fairly fast claim. I had a heart attack, found 100% blockage in one of my arteries in the emergency room and had a single stent put in. Ended up spending 4 days in the hospital. Found out about AO when doing research why this happened to me...no one in my family has ever had heart problems. Went to the VA with my medical record, proof of "on the ground" in Vietnam, submitted my claim, had a C & P about a month later and then was awarded 60%, Whole thing lasted 3-4 months...fast in the VA world. If memory serves, I got 100% for a single month and then it adjusted to 60% thereafter going back to the day I submitted the claim.
I second the recommendation to get on e-Benefits so you can stalk your claim and find out quickly what your award is by printing out the letters after your claim is complete.