The 411 on Pacemakers

Your heart is a complex organ that normally beats at a rate of 60 to 100 beats per minute. But if it's not doing its job or starts getting sluggish, your doctor may suggest getting a pacemaker.

This little device, usually placed under your skin during a minor surgical procedure, is situated close to your heart and helps to regulate your heartbeat. During the procedure, the cables of the pacemaker are threaded through the blood vessels to the upper and lower chambers of the heart.

"Pacemakers are life extending," says Ranjit Suri, MD, director of the Electrophysiology Service and Cardiac Arrhythmia Center at Lenox Hill Hospital in New York City. "Not only can they prolong life, but they prevent passing out spells that can lead to injury."

And, Suri says, pacemakers permit the use of medications that are essential for people with co-existing heart problems. Otherwise, these medications, which can slow the heart further, could not be used safely.

While pacemakers are extremely safe, there are some side effects to be aware of. Here's what to expect. All of these side effects, fortunately, are very uncommon.

1. Infections. At the time the pacemaker is put in, one percent of patients or even fewer contract an infection, says Anne Curtis, MD, the Charles and May Bauer professor and chair of the department of medicine at the State University of New York at Buffalo. "If this happens, it all has to be removed and then put back in," Curtis says. "But it is very rare."

A device-related infection could also set in after the pacemaker has been in place for awhile, Suri says. "If you're on dialysis or in an immune-compromised state, you could run into this," he says. "If it happens, you'd have to take out all the hardware, eradicate the infection, and reimplant the pacemaker on the other side."

2. Blood clots. Another infrequent complication is when a blood clot develops in the vein where the wires to the pacemaker are located.

"The wires from the pacemaker that go into the heart get there from a vein," Curtis explains. "Occasionally people can get a blood clot where the vein is." While it could cause no symptoms, this could also cause the arm to swell. The treatment is for the person to take a blood thinner until the clot dissolves."

3. Electromagnetic interference. "There is a small risk of interference with electromagnetic energy in the environment," Suri says. This could involve cell phones, MRI scans, or anti-theft devices in stores. Just three weeks ago, he says, the FDA approved an MRI-compatible pacemaker.

If you have a pacemaker, you'll probably be told not to keep your cell phone in your shirt pocket on the same side where the pacemaker is, or to hold the phone to your ear on the pacemaker side. "This could cause electrical interference due to the signals that emanate from the cell phone," Curtis says.

4. Allergies. In very rare cases, someone could be allergic to the dye (if used) or to the anesthesia itself.

5. Batteries need replacing. "You can live for 50 years with a pacemaker and die of something else," Suri says. "But about every 10 years, the batteries need to be replaced, and this requires surgery."

Mayo Clinic: Pacemaker