I had to balance heart and kidneys for a while with Neko. For the longest time it was just mild hypertrophic cardiomyopathy, and mild kidney disease and I didn't do anything but make sure food was low phosphorus and add plenty of water to the food. Then the kidneys got worse, the vet suggested adding fluids, which led to a heart failure incident and a heart block/myocarditis diagnosis. The main symptom was lack of appetite. At the same time she got a small cell lymphoma diagnosis, but I digress. That just a added an abdominal ultrasound to the bill with the echocardiogram.
Treating the heart without damaging kidneys or vice versa, is a balancing act. Heart beats kidneys - always. Neko went on pimomedan (Vetmedin) and chlopidogrel (Plavix) for her heart. She was already on benazapril for her kidneys - sometimes heart diagnosis get that too. With luck and a strong willed cat, Neko got over her heart incident. The vets were amazed. Fluids were completely stopped.
At this point I had an internal medicine vet and cardiologist vet working tag team to find the right combination to balance heart and kidneys. We did try adding a very small amount of fluids back after several months, and unfortunately got another failure incident. Which I found out at home by seeing her resting heart rate (doesn't have to be sleeping), went from 20-22 to 26. It was that subtle a change. She did get some bolus Lasix (furosemide) at the vet, and a micro dose to go home with. It helped the heart, hurt the kidneys.
Sorry for the long story - I am glad you are getting an echo, hopefully buy someone with a cardiology specialty. It makes a big difference.
