If you are using a pacemaker to regulate your heartbeat, be careful about the proximity to your body of everyday household appliances and electrical tools as these may affect the functioning of the device, warns new research.

A pacemaker is a small device that is placed in the chest or abdomen to help control abnormal heart rhythms. This device uses low-energy electrical pulses to prompt the heart to beat at a normal rate and is used to treat problems relating to the rate or rhythm of the heartbeat.

The findings showed that pacemakers are susceptible to electric and magnetic fields (EMF) generated from powerlines, household appliances, electrical tools and entertainment electronics, in particular when programmed to maximum sensitivity or so-called unipolar sensing mode. This EMF interference, depending on factors such as the settings of the implant or strength of the field source with pacemakers, can result in bradycardia, or a slow heart rate.

"Electromagnetic interferences with pacemakers in everyday life can cause harmful interferences," said Andreas Napp, cardiologist at RWTH Aachen University Hospital in Germany. 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. Thus, "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," Napp added, in the paper appearing in the journal Circulation.

However, using dedicated device programming can effectively measure to reduce the individual risk of interference. For example, doctors can reprogramme pacemakers to a lower sensitivity to reduce EMF susceptibility, Napp said. For the study, the team tested under different conditions the impacts of EMF exposure on 119 patients with pacemakers.