https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum Münster Klinik für Kardiologie II - Rhythmologie Münster, Deutschland; 2Universitätsklinikum Münster Klinik für Unfall-, Hand- und Wiederherstellungschirurgie Münster, Deutschland
Introduction: Many modern smartphones are capable of wireless charging, which may interact with cardiac implantable electronic devices. Android smartphones utilize the Qi wireless charging standard while current Apple smartphones use the MagSafe standard which incorporates a magnet in the smartphone, possibly increasing the interaction potential.
Methods: In an isolated section of a porcine chest, sixteen CIED (6 pacemakers, 5 ICD, 5 CRT) from all manufacturers available in Germany were consecutively implanted in a subcutaneous and submuscular location and connected to an interactive heart simulator (InterSim III, IB Lang). Two smartphones (Apple iPhone 14, Google Pixel 8 Pro) were placed on top of the implantation site and signs of magnet mode induction were recorded. Additionally, both smartphones were tested when placed in a magnetic MagSafe-compatible phone case. Subsequently, in all cases of magnet mode induction, magnetic shielding was attempted by placing a 2mm thin steel plate at the back of the smartphone.
Results: The Apple iPhone induced magnet mode in 7 of 16 (44%) subcutaneously placed cardiac devices. Placed in a magnetic phone case, the Apple iPhone induced magnet mode in 6 of 16 (38%) of devices. Magnet mode induction was successfully prevented by placing a steel plate at the back of the smartphone in all cases. The Google Pixel smartphone did not induce magnet mode in any of the 16 devices when placed on top of the implantation site, regardless of whether a magnetic case was used. Submuscular ICD or pacemaker placement at a depth of 3cm from the skin level resulted in no occurrence of magnet mode induction by any smartphone. All devices were still able to be interrogated with the respective manufacturer’s interrogation unit and responded to an ICD magnet.
Conclusion: The Apple iPhone induces magnet mode in half of subcutaneously placed ICD and pacemakers due to the included "MagSafe" magnet. Neither a smartphone utilizing the "Qi" wireless charging standard, nor "MagSafe"-compatible accessories confer the same risk. Submuscular device placement and magnetic shielding with a steel plate prevents interaction with the ICD or pacemaker. The current study results may have implications for patient counselling and/or the development of smartphone cases with thin steel plates for magnetic shielding.