Flying a cat with a heart murmur?

Hi all, 

We will be moving from CT to WA in the near future, a 3000 mile trip. We're bringing two dogs and two cats - neither of the dogs is a concern, nor is one of the cats. However, Bubba has a heart murmur, in addition to being ridiculously shy. He is about eight years old, and I don't think the murmur is severe, if I remember correctly. I'm wondering what we can do to make his flight more comfortable. We will be flying with him in cabin, in a crate next to his sister's (the other cat we're bringing), will definitely have a towel or something over his crate. 

How else can we help him? I was thinking a cat thundershirt, possibly some sort of natural calming agent? If I remember correctly, sedating cats with murmurs is a bad idea. Of course, we'll be consulting with our veterinarian prior to flying, I was just hoping for any advice or experiences. Thanks!

I think working with your Vet is your best bet, as every cat is different, and how they handle stress is different.  However you handle him when you take him to the Vet would probably be the best way to handle the plane ride, whether you use a calming spray in his carrier, etc., however, remember that the airlines also have certain parameters that have to be met as far as what can be in his carrier, don't they.  (whether or not they will allow any stuffed toys, etc.) 

Good luck with the move, and especially with them at the inspection at the airport.  My sister just flew with her dog, and had to take him in and out of his carrier TWICE.  Considering how much he hates his carrier in the first place, it was a huge PIA getting him in there in the first place, then having to take him in and out was quite the ordeal, since he's over 75 lbs and she literally had to pick him up and stuff him in .  With cats, since they can bolt so easily, you've got to be extra careful during that process.