A pacemaker is a small, battery-operated device that senses when your heart is beating irregularly or too slowly. It sends a signal to your heart that makes your heart beat at the correct pace.
Newer pacemakers weigh as little as 1 ounce. Most pacemakers have 2 parts:
A pacemaker must be implanted under the skin. This procedure takes about 1 hour in most cases. You will be given a sedative to help you relax. You will be awake during the procedure.
A small incision (cut) is made, most often on the left side of the chest below your collarbone. The pacemaker generator is then placed under the skin at this location. The generator may also be placed in the abdomen, but this is less common.
Using live x-rays to see the area, the doctor puts the leads through the cut, into a vein, and then into the heart. The leads are connected to the generator. The skin is closed with stitches. Most people go home within 1 day of the procedure.
Two kinds of pacemakers -- transcutaneous and transvenous pacemakers -- are used only in medical emergencies. They are not permanent pacemakers.
Pacemakers may be used for people who have heart problems that cause their heart to beat too slowly. A slow heartbeat is called bradycardia. Two common problems that cause a slow heartbeat are sinus node disease and heart block.
When your heart beats too slowly, your body and brain may not get enough oxygen. Symptoms may be light-headedness, tiredness, fainting spells, and shortness of breath.
Some pacemakers can be used to stop a heart rate that is too fast (tachycardia) or that is irregular.
Other types of pacemakers can be used in severe heart failure. These are called biventricular pacemakers. They help coordinate the beating of the heart chambers.
Most biventricular pacemakers implanted today can also work as implantable cardioverter defibrillators (ICD), which restore a normal heartbeat.
Information provided by Medline Plus