Add Yahoo as a preferred source to see more of our stories on Google. Electrocardiograms, or ECGs, record the electrical activity of your heart. Randy Faris/The Image Bank via Getty Images Your ...

The investigative minds at Debunked explain how defibrillators function to save lives during cardiac emergencies.

Understand how defibrillators work to restart the human heart.

It felt like something inside me wound up and sucker-punched me from the inside out. The air around me got heavy.