Oh, I did not see the thread earlier. Your tribute to Katz with her web page is great!
I have seen many kitties with a heart condition at the shelter were I was helping in the Netherlands, and unfortunately what happened to Katz is common in this situation. I have seen it happening myself. But I also know these kitties have a great chance to live several years when they are well cared for, in a good home, and this is the most important.

My first kitty was also a tuxedo, a very intelligent guy I will never forget