MOT at the vets

I took Willow to the vet's this morning for her annual booster, which is pretty routine. So I was a bit surprised to find out she has a slight heart murmour.
The vet it's nothing to really worry about, but just be aware of any symptoms arising (i.e. tolerance to excercise reducing, coughing at night, weight lose etc.). She's turned out to be a pretty defective example of her species with arthritis occurring when she was only 5, and now a heart murmour aged 8.
On the plus side, the vet did say that because she is pretty fit that her heart is compensating (my words) for the irregular beat - it's sort of righting itself (I don't claim to understand cardiac physiology!), so at least she is healthy aside from the murmour, arthritis, aggressive tendencies toward other dogs, and other neurosis she's acquired over the years!