There seem to be so many things that can immerge using these machines, CA's, insomnia, fragmented sleep. Trying to find any help in the medical field is very difficult.
For myself I have been through two sessions of CPAP, bought myself a ResMed S9 VPAP Adapt, AHI down from 20 to 0-1 most nights. Played with a BiPap for 5 nights just last week, it was horrible, back on ASV now.
This sleep stuff can get difficult. I had a sleep study and titration, showed few CA's. But something clearly happens when on the machine. Only the ASV cleans up my breathing while asleep.
At least you have a sleep doc and study that shows the CA's...I would try the BiPAP, they will see within a few nights if the BiPAP will work for you. These are the medical hoops that are out there...personally I just have gone my own way as the medical system cannot help with my sleep issues.
As Papit wrote, the effect of ASV was immediate, as it was/is with me.. It is worth going through the hoops to get official help.
Thanks for sharing your success with ASV. I'm sorry that you have had difficulty with the medical system. I am finding the medical system to be helpful but insurance to be a nightmare. Your experience with ASV matches what the research literature says--that ASV is the best treatment for treatment emergent CSA. I'm now scheduled for a repeat sleep study to assess BiPAP with backup and ASV (and then I will need to do battle with my insurance company to get them to cover the cost of the 2nd sleep study).