Pacemakers

A pacemaker, also called an artificial pacemaker so as not to confuse it with the heart's natural pacemaker, works to restore as well as help the heart maintain a normal rhythm. Some pacemakers are internal, or surgically implanted, and others are external.

Who Needs a Pacemaker?
A pacemaker is used to treat those with severe forms of abnormal heart rhythms, such as bradycardia and atrial fibrillation. In addition, people whose electrical impulses in the heart are blocked or move too slowly. External pacemakers are only used to stabilize the heart beat before further treatment is done. They are usually only used in hospitals.

Internal (Permanent) Pacemakers
An internal pacemaker is a small, battery powered device that works to regulate the heart beat by sending out small electrical impulses. Although it is very small (about an inch and a half in diameter), it contains the battery, the wires that send the electricity to the heart, and the pulse generator, which produces the electrical impulses.

Internal, permanent pacemakers are surgically implanted in the chest. They are attached to the heart via a wire that goes through a vein in the neck. There are several different forms of permanent pacemakers.
Fixed rate. A fixed rate pacemaker is designed to give off electrical impulses to the heart at regular intervals
Rate responsive. A rate-responsive pacemaker varies electrical impulses based on the patient's activity level.
Single chamber. A single-chamber pacemaker only affects the ventricle, or lower chamber of the heart.
Dual chamber. A dual-chamber pacemaker regulates both the atrium (top chamber) and ventricle (bottom chamber).

A pacemaker's battery is designed to last between 5 and 15 years. Many times, pacemakers are used only as needed when they detect the heartbeat is abnormally slow or needs to be shocked back into a regular rhythm.

The surgery for inserting a pacemaker is actually minor and requires only local anesthesia. It generally takes less than an hour. During surgery, a small incision is made in the chest while the pacemaker leads are inserted into a large blood vessel in the upper chest and into the heart. Then, a pocket under the skin is made in order to hold the pulse generator. Finally, the leads are hooked up to the pulse generator.

Side Effects and Cautions of Internal Pacemakers
Although considered a successful way to treat bradycardia, there are some risks that come with an internal pacemaker. These include the chance that it will malfunction, blood clots, breathing problems, and infection at the site of the incisions. Your doctor will monitor you frequently to make sure the pacemaker is functioning and that risks are minimal.
Because the components of an internal pacemaker contain electrical equipment that can be affected by magnetic and electrical fields, patients must avoid or keep a safe distance from a number of thing. They should completely avoid MRI machines, radio transmitters, including those in toys, HAM radios, and high-voltage power lines. People with pacemakers should also stay at least a foot (12 inches) away from speakers, magnets (including airport magnet wands), and cell phones.

External (Temporary) Pacemakers
External, or temporary, pacemakers are used instead of a permanent pacemaker in a number of situations. They are used in emergency situation inside the hospital to stabilize a patient's heartbeat and are also used in place of a permanent pacemaker when a patient is too sick to receive a permanent pacemaker.