Word to describe a faint, feeble, and irregular sound?

I’m looking for a word (adjective) to describe a sound that is very weak and coming in and out. It may be aptly used to describe a dying heartbeat that is inconstant and indicative of imminent death. I initially thought the word was “feathery,” but Google tells me that’s totally off base; I mention it, nonetheless, on the off chance that the two words are similar and it may better facilitate your recall of the right word. Also, I’m fairly certain the word ends in -y.

The word should fit the following sentence –

The soldier’s breath was _____ as he lie bleeding out.