In a recent study published in the Europace Journal, researchers examined electromagnetic interference (EMI) risk for patients with cardiac implantable electronic devices (CIEDs) from high-power chargers for electric vehicles (EVs).
Study: High-power chargers for electric vehicles: are they safe for patients with pacemakers and defibrillators? Image Credit: SmileFight/Shutterstock.com
CIEDs such as pacemakers (PMs), cardiac resynchronization therapy (CRT) systems, and implantable cardioverter defibrillators (ICDs) represent the primary treatment option or adjuncts for arrhythmia/heart failure treatment.
Studies have reported on the vulnerability of CIEDs to EMI, which can cause spontaneous reprogramming, pacing inhibition, mode switching, or inappropriate detection/treatment of tachycardia.
The electromagnetic field generated by an electric device can cause EMI and induce a current in CIED circuits, which could be sensed by CIEDs and misattributed to intracardiac signals. Motors of fully electric cars are high-powered.
Device shielding and EMI detection algorithms reduce clinical EMI risk, but events still occur. Therefore, it is essential to identify and assess newer EMI sources.
About the study
In the present study, researchers investigated the potential risk of EMI due to high-power EV charging in patients with CIEDs. Patients attending routine device follow-ups were asked to participate. Inclusion criteria included transvenous devices, such as PMs, ICDs, subcutaneous ICDs (S-ICDs), and CRT systems.
Exclusion criteria were lead malfunction, leadless PMs, intrinsic heart rate above 120 beats per minute (bpm), or less than three months of battery longevity. Volunteers were invited to the IONITY test site from June to July 2021.
The team used four EVs (Audi E-Tron 55 Quattro, Tesla Model 3 Performance, VW ID3 Pro performance, and Porsche Taycan Turbo) capable of high-power charging. Additionally, they used an IONITY test vehicle with a 350-kW charge.
Six charging stations delivering 300 to 350 kW were used. The current delivered for each EV was measured per charge. Magnetic and electric fields were measured along the cable and the charging column.
CIEDs were interrogated and reprogrammed before the study to maximize EMI detection. Patients were continuously monitored with an electrocardiogram (ECG).
Patients plugged in the cable and initiated the charging of EVs and the test vehicle. The cable was positioned over/near the CIED to maximize the chances of EMI, mimicking the worst-case scenario.
After charging, CIEDs were interrogated to determine if any mode switching or spurious tachycardia detection occurred, and CIEDs were re-configured to previous settings.
Findings
Overall, 130 patients aged on average 59 performed 561 charges. CIEDs were 85 ICDs (including 33 S-ICDs) and 45 PMs. About 38% and 27% of device indications were the primary and secondary prevention of sudden cardiac death, respectively; 25% were atrioventricular (AV) block, and 10% were sinus node dysfunction.
The maximum magnetic field was 38.65 μT root-mean-square (RMS) at the charging system connector (to the EV), along the cable, and 77.9 μT at the charging station. The maximum electric field was 74.33 V/m RMS along the cable, with a 281.7 V/m peak. The highest charge delivered was 350 kW for the test vehicle, followed by the Tesla Model 3 Performance at 190 kW.
The researchers did not detect events of EMI. Specifically, they did not observe oversensing, pacing inhibition, spontaneous reprogramming, or spurious tachycardia detection. Therefore, the risk of EMI was zero out of 130 patient-based and 561 charge-based analyses.
Conclusions
The study evaluated the risk of EMI in CIED patients when using high-power chargers for EVs. The findings did not find evidence of EMI while plugging in or charging EVs.
The study comprised 53 distinct devices from six manufacturers and a range of leads, allowing for the generalization of the findings.
The researchers did not use real-time wireless electrogram monitoring, implying that sub-clinical EMI might not have been detected.
Above all, using high-power chargers by patients with CIEDs was safe without any clinically relevant EMI. The team still advocates reasonable caution because the occurrence of very rare events cannot be excluded.
