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 ...
Defibrillators and pacemakers help the heart maintain a regular rhythm. Defibrillators deliver a shock if the heart goes into arrhythmia. Pacemakers use electrical impulses to keep the heart from ...