Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

MRI Risks in Patients with a Pacemaker or ICD

N Engl J Med; 2017 Feb 23; Russo, Costa, et al

In patients with a non-MRI-conditional pacemaker or implantable cardioverter defibrillator (ICD) who underwent clinically indicated nonthoratic MRI at 1.5 tesla, were appropriately screened, and had the device reprogrammed in accordance with the prespecified protocol, device or lead failure did not occur, a recent study found. MRI was performed in 1,000 cases in which patients had a pacemaker and in 500 cases in which patients had an ICD. Researchers found:

  • No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI.
  • 1 ICD generator could not be interrogated after MRI and required replacement.
  • 6 cases of self-terminating atrial fibrillation or flutter and 6 cases of partial electrical reset were observed.
  • Repeat MRI was not associated with an increase in adverse events.


Russo RJ, Costa HS, Silva PD, et al. Assessing the risks associated with MRI in patients with a pacemaker or defibrillator. N Engl J Med. 2017;376:755-764. doi:10.1056/NEJMoa1603265.


Due to concern about the magnetic field of the MRI disturbing the implanted pacemakers or ICDs, patients with older implanted cardiac devices have generally not been able to have MRIs. Many newer pacemakers are FDA approved as “MRI-conditional” and have been developed to not react in an MRI machine. This study shows that as long as the correct protocol is used with device checking and reprograming, patients with pacemakers and ICDs are eligible for MRIs when needed. —Neil Skolnik, MD