Boa heart failure?

[caticind]

Our 16-yr old BCI had developed symptoms suggesting a respiratory infection - lethargy, loss of appetite, weight loss, and just recently wheezing. We took her straight to the exotic vet when we heard her wheezing as there's a good one locally.

They tell us she appears to have heart failure. The "RI" is secondary because she is retaining fluid, might not even be an infection. She's on an antibiotic and diuretic.

There's so little info online about boas older than 10, and practically no literature I could find on heart failure in snakes of any kind. This is a beloved snake and we hoped she'd see 30 so I want to learn anything I can. Anyone here encounter an issue like this with their snake? What did your vet say? What treatment did you give? What was the outcome?