Internal pacemaker

Alternative names
Artificial pacemaker; Permanent pacemaker; Pacemaker

A pacemaker is a small, battery-operated electronic device which is inserted under the skin to help the heart beat regularly and at an appropriate rate.


A pacemaker generally has two parts - the generator and the leads. The generator is where the battery and the information to regulate the heartbeat are stored. The leads are wires that go from the generator through a large vein to the heart, where the wires are anchored. The leads send the electrical impulses to the heart to tell it to beat.

The battery can last anywhere from 7-8 years on average and will be routinely monitored by your health care professional and replaced when necessary. The generators have become smaller over the years and often weigh less than 30 grams (a little less than an ounce).

A pacemaker can usually sense if the heartbeat is above a certain level, at which point it will automatically turn off. Likewise, the pacemaker can sense when the heartbeat slows down too much, and will automatically turn back on in order to start pacing again.

A pacemaker is often the treatment of choice for people who have a heart condition that causes their heart to beat too slowly (bradycardia).

Less commonly, pacemakers may also be used to terminate an abnormally rapid heart rate (tachycardia). The pacemaker can sense the abnormally fast heart rate and take control of it by speeding up first. Then, it can be slowed down to normal.

In most cases, the procedure for inserting a pacemaker will take approximately one hour. The patient is awake for the procedure, and pain medication is given throughout the procedure.

A small incision is made traditionally in the left side of the chest, and a small “pocket” is created underneath the skin. After the leads have been positioned in the heart under X-ray guidance, they are then connected to the generator.

The generator is then placed into the pocket, and the pocket is closed with sutures. Most patients are able to go home within 1 day of the procedure, if there are no other medical issues requiring further hospitalization.


These are possible complications during the procedure.

  • bleeding  
  • infection  
  • dropped lung (uncommon)  
  • abnormal heart rhythms  
  • puncture of heart leading to bleeding around the heart (rare)

There are only a few devices in the environment today that which can interfere with a pacemaker. The American Heart Association recommends that if you have a pacemaker, you should pay attention to your surroundings and the devices that may interfere. You should always carry identification with you that indicates you have a pacemaker.

  • Most home appliances (e.g., microwave, CB radios) do NOT interfere with the pacemaker.  
  • Currently, cellular phones in the U.S. do NOT interfere with pacemakers, but it is prudent to keep cellular phones away from the pacemaker (i.e., do not store phone in shirt pocket).  
  • Arc welding equipment and equipment with powerful magnets have the potential to interfere with the pace generator.


Johns Hopkins patient information

Last revised: December 7, 2012
by Mamikon Bozoyan, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.