Smartphones can affect pacemakers and ICDs

23rd June 2015

People with pacemakers and internal defibrillators (ICDs) should keep their smartphones away from their hearts to avoid electromagnetic interference, says a German study.

However, the interference risk is small, occurring in one of the 308 patients (0.3%) tested, Dr Carsten Lennerz, from the German Heart Care Centre in Munich, reported at a European Heart Rhythm Association conference currently being held in Milan.

Dr Lennerz and fellow researchers wanted to see if current safety recommendations from regulatory organisations, such as America’s FDA, were relevant to today’s technology.

He said the recommendations were based primarily on 10-year-old research.

"Interference between smartphones and cardiac devices is uncommon but can occur, so recommendations on keeping a safe distance should be upheld," Dr Lennerz said in an accompanying press release.

He said that pacemakers can mistakenly detect electromagnetic interference from smartphones as a cardiac signal, causing them to briefly stop working.

This led to a pause in the cardiac rhythm of pacing-dependent people and might result in a short loss of consciousness. For ICDs, the external signal mimicked a life threatening heart rhythm, leading the ICD to deliver a shock, Dr Lennerz explained.

Those studied included 147 people with pacemakers and 161 with ICDs. They were exposed to the electromagnetic fields of three common smartphones: the Samsung Galaxy 3, Nokia Lumia, and HTC One XL.

The phones were put on the patients' skin, directly above their heart device, and connected to a radio communication tester, which works like a mobile network station. The investigators then put the phones through a standardized protocol that included connecting, ringing, talking and disconnecting.

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