A native pacemaker is the electrical tissue in the heart that controls the heart rate – it is the “ticker”. Such tissue exists in many sites throughout the heart  – typically the higher you go in the heart the faster the rate of the pacemaker. This is an elegant natural design, as if there is a failure of a native pacemaker, or a block in the electrical conduction of a native pacemaker, a lower pacemaker can serve as a backup pacemaker. The slower natural rate of these “backup” pacemakers reduces the likelihood of competition between the native pacemakers.

Artificial pacemakers (what people usually mean when they use the term “pacemaker”) are electrical devices that can be connected to various parts of the heart with electrodes. They  can be used to monitor and treat arrhythmias.

Not to be confused with a spacemaker.