Abnormalities in the heart’s electrical system can cause the heart rate to be too fast or too slow. If you have a condition called bradycardia, otherwise known as a slow heartbeat, there’s a good chance your doctor may prescribe a pacemaker. Pacemakers help restore the heart's rhythm, by sending tiny electrical signals to increase the heart rate, which relieves the symptoms of bradycardia. Over the years, Medtronic engineers pushed the limits of technology, making the device smaller and smaller. In fact, today we make the world’s smallest pacemaker. But the idea behind the way the device operates is largely the same: It delivers electricity to restore normal heart function.