# Impact of magnetic fields from tablets, laptops, smartphones, and household/leisure magnets on cardiac implantable electronic devices

## TL;DR

This study shows that magnetic fields from common devices like tablets and smartphones can trigger unintended responses in heart devices when placed very close, highlighting the need for patient awareness.

## Contribution

The study quantifies the proximity thresholds for magnet mode activation in CIEDs due to modern devices and household magnets.

## Key findings

- Magnetic fields from devices like tablets and smartphones can activate CIEDs at distances as small as 0.01 mm.
- Magnet mode activation did not occur at distances of ≥20 mm for any tested device.
- Household magnets activated CIEDs at distances ≤7 mm, while tablets and laptops had the longest threshold at 18 mm.

## Abstract

Cardiac implantable electronic devices (CIEDs) activate the magnet response at a magnetic flux density of ≥10 gauss (G), which may cause unintended pacing, leading to discomfort or even severe arrhythmias. Information processing devices have recently incorporated magnets, which may activate the magnet mode in patients with abdominally implanted devices, subcutaneous implantable cardioverter‐defibrillators (ICDs), or extravascular ICDs.

We investigated the effects of the magnetic fields generated by information processing devices (tablets, laptops, and smartphones) and household/leisure magnets on 13 models of CIEDs, analyzing their association with magnet mode activation in different manufacturers' CIEDs.

The tested magnet materials exhibited a maximum magnetic flux density of 290–1360 G. The magnetic flux density distribution in the information processing devices was as follows: accessory connectors, speakers, cameras, and microphones (p = 0.0001). The median activation distances for the magnet mode were 6.5 (range, 4–15), 5 (4–11.3), and 0.01 (activated only when attached; 0–7) mm for tablets and laptops, smartphones, and household/leisure magnets, respectively (p < 0.0001). The maximum distance at which the magnetic flux density decreased below 10 G was the longest for tablets and laptop computers at 18 mm.

Information processing devices and household/leisure magnets can affect CIEDs when placed in close proximity. Among the devices tested, magnet mode activation did not occur at distances of ≥20 mm. Considering the increasing prevalence of information processing devices and the growing adoption of nonthoracic CIED placements, raising awareness among patients about potential interactions is crucial.

This study on 13 Cardiac implantable electronic device (CIED) models revealed that surface magnetic fields of tablets, laptops, smartphones, and household magnets exceeded 10 G, potentially triggering magnet response mode. Activation occurred at ≤15 mm for electronic devices and ≤7 mm for household magnets. Magnet response was not observed >18 mm. These findings underscore the risk of unintended magnet response at close proximity, necessitating patient education and healthcare professional awareness regarding safe device use and variable magnet mode operation across CIED manufacturers.