Well not that this is any help at all to you-
I have a history of panic attacks too . I got them very often as a teen-at least 1 a day. Now it seems like every few years I have a period of episodes that lasts a month or so.
It starts with hot/cold flashes. Sweating. Irritability-like I want to knock someone out. And then the heart stuff. Palpitations-that come in waves. Almost like if your heart skipped a beat. Similar to the flutters you're describing.
I am told that if it happens I have to go with it, and not fight it. That is the only thing that will make it go away. I sit with my eyes closed and do long deep breathing, drink something cool, or even chamomile tea. Put soft music on, or even a relaxing tv show.
Just remember that not all panic attacks are the same. When I first had them, it was just the heart stuff and blacking out-no other pyhsical symptoms. And I thought I was dying of heart disease and ran out for every heart test possible.
When it was DX by my cf team as panic attacks-I was told and have been told by several cf professionals since then that they are fairly common in cf patients.