'Hot Spots' No Threat For Pacemakers

Study: Wireless Networks Also Don't Affect Defibrillators Implanted In Heart Patients

(WebMD)  People implanted with pacemakers or defibrillators to protect them from life-threatening, abnormal heart rhythms have one less thing to worry about — being zapped at a wireless hot spot.

"We were unable to see any impact of the wireless systems on the operation of the pacemakers or the automatic implantable defibrillators," researcher Fritz Mellert, M.D., says of his study, presented here at the annual meeting of the American Heart Association (AHA). Mellert is a consultant cardiac surgeon at the Klinik und Poliklinik for Herzchirugie, at the University of Bonn, in Germany.

"In no case did a pacemaker stop pacing when it should or pace when it shouldn't," Mellert tells WebMD. "And none of the implanted defibrillators gave a shock when they shouldn't, or didn't fire when they should."

In the study, researchers placed 25 different types of pacemakers and 22 different types of defibrillators in a device simulating the human body. Each was then exposed to the 1,000 megawatts of transmitting power authorized in the U.S., as well as to the lower 100-megawatt transmitters used in Europe.

Five pacemakers tested within 24 inches of the high-frequency transmitters did experience minor scrambling of monitoring signals, creating some noise, "but it would not have interfered with their operation," says Mellert.

None of the defibrillators was affected by data transmissions.

While some airports and restaurants post signs, "people often don't know when they are close to a wireless hot spot," Mellert says. "Since these systems are being set up everywhere — in offices, restaurants, hospitals, and homes — these findings should offer some reassurance."

Elliott M. Antman, M.D., an AHA spokesman and a heart specialist at Harvard Medical School, says "a lot of people given pacemakers or implanted defibrillators are given very strict information about things they need to be cautious about.

"If we can reduce the number of environmental factors that they need to worry about, they will have a greater sense of comfort with their device," Antman tells WebMD. "This would improve their quality of life."

SOURCES: American Heart Association's Scientific Sessions 2006, Nov. 12-15, 2006, Chicago. Fritz Mellert, M.D., consultant cardiac surgeon, Klinik und Poliklinik for Herzchirugie, University of Bonn, Germany. Elliott M. Antman, M.D., AHA spokesman; professor of medicine, Harvard Medical School, Boston.