Facing choices

I'm off to pick up Ceilidh at the vet in a few minutes. She spent the day getting checked out - the vet said the heart murmur she found last year had worsened considerably - from a grade 1 to a grade 3. Ceilidh's only seven years old, and we don't even want to consider the implications if she has exercise restrictions. Not the full-speed, party girl! We're dreading having to face the choice - quantity or quality of life?