Mary, I'll add my two cents to the "me, too!" list. I have a heart murmur (with the fairly ominous-sounding name of "aortic insufficiency"), and as a result of that I have to do the following things differently in my life:

ABSOLUTELY NOTHING!

I can imagine how freaked out you are by Specs' diagnosis, but it sounds as though you have a fabulous vet -- and as you're seeing here in this thread, a heart murmur, more often than not, is usually not as scary as it sounds.

((((((HUGS)))))) to you and Specs!

Diana