Effects of electro-shockers for self-defense on cardiac implantable electronic devices

Introduction: Electro-shockers are commonly used for self-defense and are freely available for purchase by adults in most countries. While the interaction potential with cardiac implantable devices is apparent, no data are available concerning the effect of electro-shocker use on cardiac implantable devices.

Methods: Sixteen cardiac implantable electronic devices (6 pacemakers, 5 ICD, 5 CRT) from all manufacturers (4 Medtronic, 3 Abbott, 3 Boston Scientific, 3 Biotronik, 3 Microport) were utilized. In an isolated section of a porcine chest, devices were consecutively implanted in a subcutaneous and submuscular location and connected to an interactive heart simulator (InterSim III, IB Lang). Three commercially available electro-shockers (“PowerMax”, 500.000 Volt; “Electric Guard”, 250.000 Volt; “Bikenda”, <50.000 Volt) were successively applied to the skin of the porcine chest and signs of oversensing or interaction with the device were noted. Subsequently, all devices were checked for functional integrity.

Results: No permanent damage to any of the pacemakers, ICD, or CRT was noted during testing. The highest rate of interaction was documented with the “PowerMax” electro-shocker, with 16 of 16 devices (100%) inhibiting stimulation during electro-shock application and 8 of 16 devices (50%) storing an episode of ventricular oversensing. Application of the “Electric Guard” electro-shocker resulted in inhibition of stimulation in 9 of 16 devices (56%) and a stored ventricular high-rate episode in 2 of 16 devices (13%). The rate of oversensing was the lowest with the “Bikenda” electro-shocker, with inhibition of stimulation in 1 of 16 devices (7%) and storage of a ventricular high-rate episode in none of the 16 devices. There was no relevant difference in the incidence of interaction when subcutaneous device placement was compared to submuscular device placement (risk of interaction 39% vs. 36%, p=0.88).

Conclusion: Electro-shockers for self-defense pose a substantial risk for interaction with cardiac implantable devices. The individual risk seems to be primarily dependent on applied voltage by the electro-shocker. Submuscular device placement did not substantially reduce risk of interaction when compared to subcutaneous placement. No permanent damage to the tested pacemakers and defibrillators was noted, even when shocks were applied near the devices.