Work

Electromagnetic Interference and Thermal Effects of an Ultra-Low-Field MRI in Temporary and Permanent Pacemaker Systems: An Ex Vivo Evaluation

Year: 2026

Type: article

Abstract: Background Magnetic resonance imaging in patients with cardiac implantable electronic devices carries risks of oversensing, pacing inhibition, and lead heating. While MRI-conditional devices have expanded imaging access at conventional field strengths (1.5–3T), safety data at ultra-low field strength (0.064T) remain limited, particularly for temporary pacing systems. Objective To evaluate electromagnetic interference, pacing inhibition, and thermal effects of a 0.064-T point-of-care MRI system in temporary and permanent pacemaker systems in an ex vivo setting. Methods Temporary epicardial pacing systems and an MRI-conditional permanent pacemaker were evaluated during a complete brain MRI protocol using a 0.064-T scanner (Swoop®, Hyperfine). Commercially available temporary (Ethicon TPW20 temporary pacing wire; Medtronic 5433V ventricular cable) and permanent (Azure™ XT DR MRI SureScan™, Medtronic Model W1DR01 ventricular leads; Medtronic CareLink 2090 Programmer) pacing systems were monitored for device function, output, and heating. The threshold for inhibition of pacing was observed using graduated ventricular sensitivity settings. Results Temporary pacing systems demonstrated predictable, sensitivity-dependent oversensing and transient pacing inhibition at nominal ventricular sensitivity settings, resolving at higher sensing thresholds. No oversensing or pacing inhibition occurred in the permanent pacemaker system at standard programming parameters. No irreversible device malfunction or measurable electrode tip heating occurred during any sequence. Maximum observed temperature variation was <0.5°C from baseline. Conclusion Ultra–low-field (0.064-T) MRI did not induce clinically meaningful thermal effects or permanent device dysfunction in temporary or permanent pacemaker systems in an ex vivo setting. Transient oversensing in temporary systems is mitigated by programming adjustments. These findings support cautious progression toward clinical evaluation of low-field MRI in pacemaker-dependent patients.

Source: Heart Rhythm O2

DOI: 10.1016/j.hroo.2026.08.148