Magnetic Resonance Imaging and Implantable Devices

Section of Cardiac Electrophysiology, The Johns Hopkins University School of Medicine, Baltimore, MD.
Circulation Arrhythmia and Electrophysiology (Impact Factor: 5.42). 04/2013; 6(2):419-428. DOI: 10.1161/CIRCEP.113.000116
Source: PubMed
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    ABSTRACT: To assess the current knowledge about the potential hazard from MRI in patients with devices such as pacemakers and implantable cardioverter defibrillators (ICDs). Most data concern 'MRI unsafe' devices, with only a few studies on 'MRI conditional' devices. No 'MRI safe' cardiac devices are currently available. Studies on 'MRI unsafe' devices tend to be small scale and reflect the experience of individual centres; few provide long-term follow-up data. Many newer devices are approved as 'MRI conditional' based on technical simulations or postmarket surveillance studies. With adequate measures taken before performing an MRI scan, reported complication rates are generally low, but there is a nonnegligible residual risk for power-on reset and lead heating. The presence of abandoned, older leads may affect the propensity for lead heating during MRI with newer devices, including those designated 'MRI conditional'. Very little research has been carried out on the hazard from MRI scans in patients with ICDs, but registry data indicate more events with ICDs than with pacemakers. The limited available data indicate a manageable but not negligible MRI-associated hazard in patients with implantable cardiac devices. Further controlled studies and large, independent registries, particularly in Europe, are needed to provide important safety information.
    Current Opinion in Cardiology 01/2015; 30(1):65-73. DOI:10.1097/HCO.0000000000000132 · 2.59 Impact Factor
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    ABSTRACT: Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively.
    The Canadian journal of cardiology 10/2014; 30(10):1131-41. DOI:10.1016/j.cjca.2014.07.010 · 3.94 Impact Factor
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    ABSTRACT: Use of both magnetic resonance imaging (MRI) and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radio frequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitations prompted a series of modifications in generator and lead engineering, designed to minimize interactions that could compromise device function and patient safety. The resulting MRI-conditional pacemakers were first introduced in 2008 and the clinical experience gathered so far supports their safety in the MRI environment if certain conditions are fulfilled. With this technology, new questions and controversies arise regarding patient selection, clinical impact, and cost-effectiveness. In this review, we discuss the potential risks of MRI in patients with electronic cardiac devices and present updated information regarding the features of MRI-conditional pacemakers and the clinical experience with currently available models. Finally, we provide some guidance on how to scan patients who have these devices and discuss future directions in the field.
    Medical Devices: Evidence and Research 05/2014; 7:115-124. DOI:10.2147/MDER.S44063