Pacemaker wearers should keep distance from interfering smartphones
Mon 22 Jun 2015
Researchers have warned those who wear a pacemaker or other cardiac devices to ensure they hold their smartphones to the opposite ear and to keep the handset away from the chest.
According to Carsten Lennerz at the German Heart Centre, Munich, the electromagnetic interference (EMI) can cause the pacemakers to malfunction, briefly pausing the cardiac rhythm, which can lead to fainting.
Lennerz explained in a presentation at the European Society of Cardiology this week that “pacemakers can mistakenly detect electromagnetic interference from smartphones as a cardiac signal, causing them to briefly stop working.”
Meanwhile for patients dependent on implanted defibrillators, Lennerz said that the smartphone signals could replicate a “ventricular tachyarrhythmia” To correct what it thinks is a life-threatening trauma the device delivers a painful shock to regulate the rhythm.
The cardiac experts tested 308 patients using three different smartphones –Samsung Galaxy 3, Nokia Lumia, and HTC One XL. The pool included 147 patients fitted with pacemakers, 161 with implantable cardioverter defibrillators (ICDs) and 65 treated with cardiac resynchronisation therapy (CRT).
The testing was performed in GSM, LTE and UMTS systems at maximum transmission power and at 50 Hz – a frequency understood to cause interference. Electrocardiograms (ECGs) were recorded continually and monitored for EMI.
When the phones were placed on the skin above the medical device and received a call, one patient out of 308 (0.3%) was affected by the smartphone signals from the Nokia and HTC handsets.
A safety distance of between 15cm and 20cm should be kept between a medical device and mobile phone, as recommended for more than a decade by manufacturers and other industry regulators such as the U.S. Food and Drug Administration.
Since then smartphones have been introduced and cardiac devices significantly developed. The study found that although interference is rare, it was important to maintain the suggested safety distance.