No one who posts here does this, but all you other folks, try to remember that it's "bated breath," not "baited breath."
"To bate" is a transitive verb meaning to reduce the force or intensity of something. Thus, when you have bated your breath you are restraining it. In other words, this is a different idiomatic way to say you're holding your breath.
"To bait" is to lure something, like fish or vermin, with food or some other enticement. Thus, if you ate a lot of Limburger cheese, you might have "baited breath"—and you might expect to attract mice with it.