Can a patient undergo Magnetic Resonance Imaging (MRI) with an implantable loop recorder (ILR)?

From the Guidelines

Yes, a patient can undergo Magnetic Resonance Imaging (MRI) with an implantable loop recorder (ILR), but it depends on the specific type of ILR and adherence to certain conditions. Most modern loop recorders are MRI-conditional, meaning they can safely undergo MRI scans under specific conditions, such as using 1.5 or 3 Tesla MRI machines and following particular scanning parameters 1.

Key Considerations

• The ILR model and its MRI compatibility must be verified by the healthcare provider before scheduling an MRI.
• The radiologist and cardiologist should coordinate to ensure proper protocols are followed.
• Some older loop recorder models may not be MRI-compatible, so it's essential to know exactly which device the patient has.
• Newer loop recorders are designed with materials and electronic components that minimize interaction with the strong magnetic fields used in MRI machines, preventing device malfunction or tissue heating.

Precautions and Protocols

• Patients with leads that have not matured (<6 weeks since implantation) and those with epicardial and abandoned leads should be excluded from MRI scans 1.
• The device should be programmed to an asynchronous pacing mode in PM-dependent patients to avoid inappropriate inhibition of pacing due to detection of electromagnetic interference.
• Other pacing functions, such as magnet, rate, noise, PVC, ventricular sense, and AF response, should be deactivated to ensure that sensing of electromagnetic interference does not lead to unwarranted pacing.
• Tachyarrhythmia monitoring and therapies (ATP/shock) should be deactivated to avoid delivery of unwarranted therapies.
• The device should be re-programmed immediately after the MRI examination.

MRI Compatibility

• The European Society of Cardiology (ESC) guidelines provide recommendations for the management of patients with implantable cardiac devices, including ILRs, undergoing MRI scans 1.
• The guidelines emphasize the importance of verifying the MRI compatibility of the ILR and following specific protocols to ensure safe scanning.

From the Research

MRI Compatibility with Implantable Loop Recorders (ILRs)

• Patients with ILRs can undergo MRI scans, but precautions should be taken to avoid potential interactions 2, 3, 4.
• Studies have shown that MRI scanning of ILR patients can be performed without harm to the patient or permanent damage to the ILR 2, 4.
• However, artifacts mimicking arrhythmias are common and must be excluded to avoid mistakenly attributing symptoms to the artifacts produced from MRI exposure 2, 4.

Safety Precautions

• The ILR memory should be cleared before MRI, and no changes should be made to programmed settings 2, 4.
• Device interrogation should take place immediately after the scan to verify the integrity of the signal and time date stamp 2.
• Patients should be surveyed for device movement, heating, and cardiopulmonary symptoms after their MRI 2, 4.

Feasibility of MRI in ILR Patients

• MRI is feasible in patients with ILRs, and with appropriate precautions, it can be performed without immediate morbidity or mortality 3.
• Local follow-up data has shown no device malfunction or adverse effects in patients with ILRs who underwent MRI 3.
• However, electromagnetic interference from MRI can potentially cause irreversible errors in ILR function, and physicians should be aware of possible malfunctioning of these devices 5.