What could happen if you held your breath when attached to a heart monitor? Would it show a "flatline"?

Flatline. 'Flatline' happens when there is no electrical activity in the heart on the ecg. This would take a long time to happen with breath holding. If there isn't a problem with the monitor or the leads, flatline means you're dead unless something is done quickly and the something works.

Related Questions

I have a implanted heart monitor. Been working outside in sun, for 2 hours hard time catching my breath and dizzy. What should I do. Aspring, or 911?

Only you know. You should definitely hydrate yourself with water, avoid going back out into the sun, and relax. As far as calling 911 that can only be your decision depending on how you feel. Ask your doctor for some tips on how to pace yourself and what to do when working outside in hot weather for future reference. Read more...