Electric cars and high power chargers: Are they safe for patients with cardiac implantable electronic devices?

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Public Institution(s). Main funding source(s): Deutsche Stiftung für Herzforschung research grant BACKGROUND: Electromagnetic interference (EMI) poses a risk to patients with cardiac implantable devices (CIEDs) and can result in device malfunction including pacing inhibition or inappropriate shock therapy. Such EMI sources are ubiquitous in the modern world. Battery electric vehicles (BEVs) represent such a potential EMI source. We have previously investigated the EMI risk of driving eCars and found that the largest electromagnetic field is located along the charging cable. New high power chargers deliver higher currents (facilitating rapid recharging), potentially associated with greater electromagnetic fields and higher risk for clinically relevant EMI. This present study aims to evaluate this EMI-risk to address this clinically important question. METHODS: A consecutive group of 130 patients with a range of CIEDs were recruited to participate. After a complete device interrogation each had their device programmed to optimise EMI detection with ensured ventricular pacing and ICD therapies were disabled. Under continuous 6-lead ECG monitoring each patient then plugged in and charged four different BEVs (Porsche Taycan Turbo, VW ID3 pro, Tesla Model 3 and Audi e-tron 55 Quattro) in addition to a ‘dummy’ eCar (which permitted the maximal charging power flow of 350kW) with the charging cable placed directly over the device. During charging both the magnetic field and electric field was measured. A further complete device interrogation was then performed to evaluate for spontaneous reprogramming and tachycardia detection. RESULTS: In total 561 separate charging events were performed by 130 patients with the four eCars and one dummy car. The maximal magnetic field along the charging cable was 38.65µT and at the charging column was 77.9µT. There were no incidences of EMI, specifically there was no pacing inhibition due to oversensing, no spontaneous reprogramming and no tachycardia over-detection. This results in a patient-based risk of 0% (95% CI; 0% - 2.8%) and a charging event-based risk of 0% (95% CI; 0% - 0.6%). CONCLUSIONS AND DISCUSSION: We found that there was no EMI induced during the use of high power charger technology for BEV despite device programming and charging cable placement being optimised for a worst-case scenario and maximising the chance of clinical EMI. Our study suggests that there is a very low risk, if any, posed by BEVs and the new high power chargers. CIED patients should reassured that their use is safe. We would still recommend not to place the charging cable directly above the CIED during use to maximise safety of high power charging.