How to use "heartbeat" in a sentence

As her heartbeat slowed, she eased back onto her pillow.

Gradually Vivienne's heartbeat subsided from the hard, frantic rhythm that it had been keeping for the past couple of minutes

Furthermore, this was not the mid-nineteenth century; these days, doctors could detect even the vaguest heartbeat, the shallowest respiration, the dimmest traces of brain-wave activity.

Her heartbeat became less like the pounding of a jackhammer, but it still did not settle into a normal rhythm; now it was affected by excitement rather than terror

There was no heartbeat whatsoever, not even a faint lub-dub.

Zachariah moved to another bank of computer screens, where Danny Evans's heartbeat, blood pressure, body temperature, and brainwave activity were constantly displayed