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 ...

Defibrillators use electrical shocks to restore a normal heart rate, especially in cases of life threatening arrhythmias or sudden cardiac arrest, while pacemakers use low-energy electrical pulses to ...

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 ...