Your heart’s job is to keep your pulse steady to pump blood throughout your body. Sometimes your heart rate is slower when you’re relaxing, and sometimes it’s faster when you’re exercising or stressed ...

During an average lifetime, the heart beats more than 2 billion times. To you, it might just be a steady “lub-dub” that speeds up under pressure and slows as you drift to sleep. But behind that rhythm ...

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 ...