MRI in patients with pacemakers: overview and procedural management.

Background: Magnetic resonance imaging (MRI) is generally contraindicated for patients with a pacemaker (PM) or implantable cardiac defibrillator (ICD), because of the risk of life-threatening interference with the device. Nevertheless, the question whether to perform MRI despite the presence of these devices can still arise when MRI is vitally indicated. In some hospitals, special precautionary measures are taken so that MRI can be performed in such cases.

Methods: This review is based on the authors' experience in 42 patients who underwent MRI at our university hospital, on the pertinent literature, and on the recommendations of medical societies.

Results: Because of its excellent image quality, MRI is often an indispensable diagnostic tool. Structured multidisciplinary management enables it to be performed safely even in patients with a PM or ICD. Pre- and post-MRI checks of the device are recommended, as well as extensive monitoring and the availability of the necessary personnel to deal with an emergency. In general, the pacing and defibrillator functions should be deactivated; for pacemaker-dependent patients, the asynchronous pacing mode should be activated. No serious incidents have occurred when these precautions have been observed, either among our own patients or in the literature. Newer PM systems have been approved for MRI scanning under certain conditions.

Conclusion: In patients with a PM or ICD, the benefit of MRI may far outweigh its risks if the indication has been established for the particular patient as an interdisciplinary decision and if the appropriate precautions are observed during scanning. Now that newer PM systems have been approved for MRI scanning, the problem seems close to being solved.