Safety of MRIs in patients with pacemakers and defibrillators

With a burgeoning population, increases in life expectancy, and expanding indications, the number of patients with cardiac devices such as pacemakers and implantable cardioverter defibrillators continues to increase each year. A majority of these patients will develop an indication for magnetic resonance imaging (MRI) in their lifetime. MRIs have established themselves as one of the most powerful imaging tools for a variety of conditions. However, given the historic safety concerns, many physicians are reluctant to use MRIs in this patient population. In this paper, we discuss the potential adverse effects of MRIs in patients with cardiac devices, review key studies that have addressed strategies to limit adverse effects, and provide our cardiovascular MRI laboratory's protocol for imaging patients with implanted cardiac devices.