Magnetic resonance imaging-induced artefact mimicking torsade de pointes in a patient with an implantable cardiac monitor: a case report

Abstract Background Magnetic resonance imaging (MRI) is increasingly performed in patients with cardiac implantable electronic devices. Although generally considered safe under specific protocols, electromagnetic interference may still lead to clinically misleading recordings. Case summary A 76-year-old woman with a history of mitral valve replacement and paroxysmal atrial fibrillation underwent implantation of an implantable cardiac monitor (Abbott Confirm Rx™) for evaluation of recurrent dizziness. During brain MRI at another hospital (1.5-T GE SIGNA Creator), the device captured high-amplitude polymorphic signals resembling torsade de pointes, whereas a simultaneous 12-lead electrocardiogram confirmed sinus rhythm with a normal QT interval. A repeat MRI at our institution using a 3.0-T Siemens MAGNETOM Lumina scanner with the same time-of-flight magnetic resonance angiography sequence did not reproduce the artefact. Phantom testing on the outside hospital’s scanner also failed to demonstrate the phenomenon. However, the artefact was reproducibly observed during a follow-up MRI performed 6 months later using the same scanner. No similar findings were observed in other patients with implantable cardiac monitors scanned using the same system. Discussion MRI-related artefacts in implantable loop recorders have been previously reported. The present case demonstrates a reproducible torsade de pointes-like morphology specifically associated with the prescan phase on a particular MRI system, suggesting a device–scanner–patient interaction rather than true arrhythmia.