Renee, I also had AC chemo in 1998 and was given the same info about possible heart damage.  I recently went through some tests for possible heart concerns and asked about whether my previous chemo could be a factor.  According to my doctors, damage from the chemo would usually show up sooner than ten years, but sometimes it is a long-term side effect.  My doctors also believe that the immune system bounces back after chemo, but my own experience is that I am more likely to catch things than I used to be.  There is probably no way to know now how much of a factor the chemo is in  your current health problems.  I do know other cancer patients who had to stop chemo because their Ejection Fraction dropped who were able to resume it later when they improved.  However, I don't know what they did to get better.  Your situation sounds complicated because you are treating more than one condition.  Are your doctors talking to one another?  You might consider a second opinion about what can be done since yours is a complex case.