I was drinking beer with a friend yesterday...as I layed on my couch I noticed heartburn since I was drinking on an empty stomach.
I felt the classical burning in my throat and suddenly I can't breath anymore.
Turns out a mix of beer and stomach acid made it's way into my lungs, hindering me from breathing.
I didn't know what happened but after a minute it opened up again. My lung hurt for the next hour and my breathing sounded like I had asthma, because of the fluid still inside.
Anyway, never drink or sit out heartburn in a horizontal position! :)