13 year old Beagle had bad ultrasound

She has been on Enalapril to prevent her heart murmur (Mitral Valve issue) from getting worse for years but this last ultra sound showed her atrium as stretched as the vet has ever seen so he's adding Pimobenden on board immediately. She's not in congestive heart failure as her x ray was clean and there is no fluid in her lungs but he's going to treat her as if she is because that atrium is so stretched.

He said once her respiratory rate reaches the mid 30s per minute he will add in Lasix and baby aspirin but we have no idea how quickly that will happen or how much this Pimobenden will help.

I knew when she was diagnosed with a level three heart murmur all the way back in 2008 that this day would come, but it's still so shocking and sad. The one thing we want to MAKE SURE of is that she doesn't suffer and we don't wait too long so we are going to stay on top of this like crazy. Right now her quality of life is good but I guess I have to come to the realization that she won't be around for more than another year or so right?