Pacemakers not only regulate heart rate, but also record the heart's electrical activity and rate, according to the National Heart, Lung and Blood Institute. After a pacemaker is surgically inserted, it must be programmed for that patient's specific needs, states The Mayo Clinic.
There are three types of pacemakers, according to WebMD. Single-chambered pacemakers have only one lead that sends electrical signals to either the upper or lower chambers of the heart. Dual-chamber pacemakers have one lead in the an upper chamber and another lead in a lower chamber. Biventricular pacemakers have three leads: one on the right atrium and one in each of the two ventricles.
Pacemakers are most frequently used to treat heart arrhythmias, which cause the heart to beat too slowly or quickly, according to the National Heart, Lung and Blood Institute. They not only keep the heart rate in check, but they also alleviate common arrhythmia symptoms such as fatigue and fainting, allowing a patient to return to a more active lifestyle. Patients suffering from problems such as a slow heart beat following a heart attack or medication overdose may be fitted with a pacemaker temporarily; it is removed before the patient leaves the hospital. Patients with long-term heart rate issues, however, typically have permanent pacemakers implanted and go back to their normal routines with the pacemaker in place.