Magnetic resonance imaging (MRI) has become a widely used imaging modality given its ability to provide high-quality anatomical and physiological data without the need for ionizing radiation [1]. Along with the increased utilization and diversification of MRI, the rate of cardiac implantable electronic device (CIED) placement has rapidly increased over the past decade. Historically, unless urgently required, the presence of a CIED was regarded as a general contraindication to undergoing an MRI. Given this contraindication, many patients were denied the benefits and diagnostic accuracy of MRI. The primary concerns with the use of MRI in patients with a CIED are related to the potential negative effects of strong electromagnetic fields on the device. These effects include, but are not limited to, device movement, programming changes, initiation of asynchronous pacing, activation of tachyarrhythmia therapies, or the inhibition of demand pacing [[2], [3], [4], [5]]. Following the placement of a CIED, up to 75% of patients will necessitate an MRI at some point in their life [[6], [7], [8]]. Significant efforts have been made to safely offer MRI to patients with CIEDs, including the revolutionary development of MR conditional devices.

CIEDs are categorized as magnetic resonance (MR) conditional or MR nonconditional [9,10]. MR conditional devices are engineered so that their leads and generators are safe in the MRI environment. In contrast, MR nonconditional devices, which lack specifically modified components to withstand strong electromagnetic environments, are not recommended to undergo MRI if alternative imaging can be performed [11]. Prior to the release of MR conditional CIEDs, smaller in vitro and in vivo studies demonstrated that MRI could be safely performed in patients with permanent pacemakers (PPM) under close electrophysiologic monitoring [[12], [13], [14], [15], [16], [17]]. Shortly following these studies, experts also concluded that patients with implanted cardioverter defibrillators (ICD) could also undergo MRI under similar supervised conditions [[18], [19], [20]]. Despite these studies, there have also been several studies that have noted multiple undesirable changes in device parameters peri-MRI in patients with these MR nonconditional devices [21,22]. Following U.S. Food and Drug Administration approval in 2011, multiple large studies have highlighted the safety of MR conditional devices in patients undergoing both cardiac and noncardiac MRI [4,[23], [24], [25], [26]].

According to the Heart Rhythm Society (HRS), the performance of MRI in patients with CIEDs requires detailed institutionalized protocols beyond the recommendations outlined in their 2017 expert consensus statement [27]. Therefore, institutional protocols have been developed to assist with the preprocedural and periprocedural MRI-management of patients with CIEDs. Studies evaluating these protocols have found that they are feasible, easily replicated, and allow for patients with CIEDs to safely undergo MRI scans [9,10,[28], [29], [30]]. Furthermore, these studies suggest that the decision to reprogram a device or asynchronously pace during an MRI can be reached by following a set protocol rather than requiring direct instruction from a patients' cardiologist. Based on the 2017 HRS expert consensus recommendations, our institution, guided by a multidisciplinary team of electrophysiologists, radiologists, radiology technologists, and electrophysiology (EP) nurses, developed a standardized, easily replicated approach for completing MRI in patients with MR conditional CIEDs. Our goal was to design a protocol that could be primarily technologist driven to allow for less direct electrophysiologist supervision during the MRI procedure. The purpose of this study was to retrospectively evaluate the PACED-MRI (Pacing and Cardioverting Electronic Devices peri-MRI) protocol, for patients with MR conditional CIEDs undergoing MRI scans at our academic institution.