Take the D scale for example. Start on the D note at the second fret and move up the scale like this to the next D: If you play this same pattern up two frets (so the E is the first note you play), youâll have an E major scale. The same goes for any other pattern you can spot in these scale maps.
A pacemaker signals the heart to beat when the heartbeat is too slow or irregular. A pulse generator is a small metal case that contains electronic circuitry with a small computer and a battery that regulate the impulses sent to the heart.
Once the pacemaker is implanted, the leads carry signals back from the heart. The pulse generator reads these signals and the batteries send electrical impulses to the heart to help pace it. Most pacemakers can sense the heart's rhythm and turn themselves off when the heartbeat is above a certain level. They will turn on again when the heartbeat is too slow. These types of pacemakers are called demand pacemakers.