HCM is manageable for a while, if you really stay on top of it and follow the cardiologists recommendations and treatment.
I would strongly recommend that you stick with this new hospital/clinic and not go back to the first one.
I would also suggest that you start calling around to several human pharmacies to get prices for the drugs, esp. Plavix and Lasix that Kula may end up getting. Prices vary quite a bit from store to store, and you will probably not have insurance to cover them.
With HCM, they will probably want to avoid anything that retains water in her body. If you need something for constipation, you can use plain canned pumpkin. It can get harder to find in the summer, so if your grocery store still has some, you might want to buy a few cans to keep in your stash. I had to mix that in my Willy's can food to keep him moving. He had kidney disease on top of the the HCM, so we had quite a balancing act to keep his heart "dry" and kidneys "wet."
Hugs for you and Kula, and I hope she can come home this weekend.