An algorithm for pacing and cardioverting electronic devices undergoing magnetic resonance imaging: The PACED-MRI protocol

Cardiac implantable electronic devices (CIEDs) have traditionally been a contraindication for magnetic resonance imaging (MRI). However, there is an increasing amount of literature to suggest that MRI can be safely performed in select patients with pacemakers and implantable cardioverter defibrillators by following a standardized protocol. We created an institutional protocol, made accessible as an online form, that is primarily technologist-driven and does not require direct electrophysiologist supervision. The purpose of this study was to evaluate the PACEDMRI protocol for screening and completing MRI in patients with MR conditional CIEDs. After the implementation of our standardized PACED-MRI protocol, patients with MR conditional CIEDs who were referred for MRI were included in the study. On the day of the MRI, the device company representative utilized our protocol accessed through PACEDMRI.com. If all parameters and criteria within the protocol were met, the examination proceeded. The device representative programed the CIED to the appropriate mode for MRI as instructed by the PACED-MRI protocol. CIED interrogation was performed immediately before and after MRI. The on-call electrophysiology nurse practitioner was notified only if the protocol instructed the team to not proceed with MRI. CIED programming changes, malfunctions, and intraprocedural events were documented. Additionally, any adverse outcomes were recorded including peri-MRI symptom onset, arrhythmia, and death. One hundred thirty-eight MRI examinations were performed on patients with MR conditional CIEDs (100 pacemakers: 38 implantable cardiac defibrillators). There was no incidence of symptom onset requiring early termination of the MRI, death, or arrhythmic events during or after MRI. No significant changes in lead parameters, including sensing amplitudes, lead thresholds, or lead impedances were noted on post-MRI device interrogation. Out of the 138 completed MRIs, the on-call electrophysiology provider was notified on one, non-urgent occasion. The implementation of the standardized, technologists-driven PACED-MRI protocol allowed for a multidisciplinary approach to MRI for patients with MR conditional CIEDs. This study demonstrates that the PACED-MRI protocol can be used for patients with MR conditional CIEDs undergoing MRI without the need for direct electrophysiologist supervision.