Power tools and appliances found “in daily life and occupational environments” can generate electric and magnetic fields (EMFs) that might interfere with pacemakers.

"Electromagnetic interferences with pacemakers in everyday life can occur, however, harmful interferences are rare using vendors' recommended device settings," Dr. Andreas Napp, study author and cardiologist at RWTH Aachen University Hospital in Aachen, Germany, advised. "Dedicated device programming is an effective measure to reduce the individual risk of interference. For example, doctors can reprogram pacemakers to a lower sensitivity to reduce EMF susceptibility."

The interference can lead to a slowing heart rate, or bradycardia. "The risk of interference depends on many different factors, such as the settings of the implant or strength of the field source. In occupational environments, such as the manufacturing industry, an individual risk assessment for workers with a pacemaker is required due to the presence of a strong EMF," he said in a statement.

To find out how susceptible implantable devices might be to EMF, 119 people with such devices were studied. The findings appeared in the journal Circulation.

Exposure in the study was to 50 Hertz or 60 Hz fields. Pacemakers with unipolar leads were found the most susceptible to interference – reacting to the mildest exposure, stated the researchers.

Those with bipolar leads were more resistant to interference – 72 percent reacted to maximum sensitivity, 36 percent to nominal sensitivity, the study found.

HCB News asked Dominik Stunder, lead engineer on the study, how the team measured the amplitude of the electromagnetic signal. He told us they did this in two ways.

First, the test system they developed to generate the electric and magnetic fields was regularly calibrated using field meter C.A 42 from Chauvin-Arnoux, France, and second, during field exposure of the patient the electric and magnetic fields were continuously monitored by current measurements using a shunt resistor.

The bottom line is that daily life is not always pacemaker-safe. “Lots of electrical appliances from daily life emit strong electromagnetic fields in very close proximity of the appliance,” Napp told Reuters.

He advised that “in many cases, holding the appliance, tool or other EMF source at a forearm’s length distance (greater than 12 inches) limits the risk of electromagnetic interference. But further measures might be needed in environments with strong EMF, such as engines used in the processing or manufacturing industry.”

If a patient thinks that they might be in an environment of powerful EMF, they should talk to their physicians.

“Patients should inform the doctors before device implantation if they are exposed to strong electromagnetic fields in daily practice or in the work environment,” Napp told Reuters. “During follow up visits in the pacemaker outpatient clinic, care must be taken while reprogramming the sensitivity of the device.”

When asked about the risks of interference, Dr. Gordon Tomaselli, chief of cardiology at Johns Hopkins Medicine, told the wire service that most tools were probably not a big problem, but he did warn about one.

“Welders are a problem, but with most other tools people would use I don’t prohibit that,” Tomaselli said. “But certainly if people are feeling odd or fatigued or having symptoms like they had before they got the pacemaker I tell them to see me or see their doctor.”

According to the American Heart Association, there are a number of common devices that can interfere with pacemakers, including:

• Anti-theft systems (also called electronic article surveillance or EAS)


• Metal detectors for security


• Some headphones


• Power-generating equipment, arc welding equipment and powerful magnets