American Heart Association journal report
DALLAS -- People with implanted defibrillators that shock the heart to regulate its rhythm may safely walk through electronic anti-theft systems, but should not linger there, according to a study in today's Circulation: Journal of the American Heart Association.
The anti-theft machines use an electronic beam to detect security-tagged merchandise being carried out of a store. The defibrillator can interpret the electronic beam as a rapid heartbeat for which the defibrillator is programmed to deliver a shock.
Douglas P. Zipes, M.D., the study's lead author, says, "There is absolutely no danger from a slow stroll through the gates, even if it takes 10 or 15 seconds."
In the study one person went through in a walker without any problems. "Now, one should not lean on or linger in theft detection devices because adverse events can happen, no question. But in normal use, there should be nothing to worry about," says Zipes, Distinguished Professor of Medicine and Pharmacology at the Indiana University School of Medicine in Indianapolis.
An estimated 400,000 people worldwide have implanted defibrillators and as many as 800,000 security systems are in use around the globe, Zipes says.
There were three recent reports of anti-theft systems causing defibrillators to fire unnecessarily, but in each case the individual lingered in the machine and in at least one instance the patient was holding on to the transmitter pole.
Previous studies were either too problematic or too small to clearly say whether the theft detectors were harmful or safe, according to Zipes.
Researchers at the Indianapolis Medical School, Methodist Hospital in Indianapolis and the Southwest Florida Heart Group in Fort Myers decided to investigate the device's response to normal use, he says.