First-of-its-kind Pacemaker System Proves to be Safe and Effective for Use During Magnetic Resonance Imaging

New study published in HeartRhythm shows no adverse complications in patients with a pacemaker system specifically designed for safe use in an MRI environment

January 06, 2011

Media Contact

Ken Demith
Heart Rhythm Society

WASHINGTON, January 6, 2011 — Results from a large, worldwide, clinical trial show evidence that a first-of-its-kind pacemaker system is safe and effective to use during magnetic resonance imaging (MRI). During the trial, no MRI-related complications were reported in patients with the pacemaker system before, during, or after an MRI examination. The data from the clinical trial, published in the January edition of HeartRhythm, the official journal of the Heart Rhythm Society, proves the ability of this pacemaker system to be exposed in a controlled fashion to MRI without negatively affecting the patient or the system. Read full text of study »

The randomized, controlled, multicenter clinical trial took place in the United States, Canada, Europe, and the Middle East, and evaluated a complete pacemaker system — pacemaker, leads, and programming of device — that was specifically designed for safe use in MRI. After successful pacemaker implantation, a total of 464 patients were randomly placed into two groups — a controlled group who would not undergo MRI, and an MRI group. Patients in the MRI group underwent MRI examinations in a 1.5-T scanner.  Both groups were evaluated one week and one month post-MRI to determine whether or not any complications occurred that could be attributed to the MRI scanning.

Of the patients in the MRI group, 100 percent were free of MRI-related complications. The MRI scans were completed safely, delivering continuous pacemaker stimulation or regular spontaneous intrinsic activation when programmed to the proper mode. None of the patients in the MRI group experienced adverse effects that have been known to occur in pacemaker patients who undergo an MRI.  Results of the trial were as follows:

During and/or after the MRI:

  • no inhibition of pacemaker output or cardiac arrest
  • no sustained ventricular arrhythmias
  • no unexpected changes of heart rate
  • no electrical resets
  • no pacemaker system disturbances and
  • no sensation of torque or pain

“Today, MRI scanning is used across many fields of medicine to help clinicians accurately diagnose patients to ensure each patient is treated properly and effectively,” stated Bruce L. Wilkoff, MD, FHRS, president-elect of the Heart Rhythm Society, Department of Cardiovascular Medicine at the Cleveland Clinic. “At the same time, the number of people living with cardiac devices is increasing and we find ourselves in need of devices that are compatible with MRI scanning. This pacemaker system is truly the first to be designed specifically for safe use in an MRI environment.”

In a proper and controlled environment, this pacemaker system has proven to be safe during MRI scanning when used in accordance with its labeling. There were no disturbances of pacemaker function and no ventricular arrhythmia induction observed in this clinical trial.

About the Heart Rhythm Society

The Heart Rhythm Society is the international leader in science, education, and advocacy for cardiac arrhythmia professionals and patients, and the primary information resource on heart rhythm disorders. Its mission is to improve the care of patients by promoting research, education, and optimal health care policies and standards. Incorporated in 1979 and based in Washington, DC, it has a membership of more than 6,000 heart rhythm professionals in more than 72 countries around the world. For more information, visit

About the HeartRhythm Journal

HeartRhythm provides rapid publication of the most important science developments in the field of arrhythmias and cardiovascular electrophysiology (EP). As the official journal of the Heart Rhythm Society, HeartRhythm publishes both basic and clinical subject matter of scientific excellence devoted to the EP of the heart and blood vessels, as well as therapy. The journal is the only EP publication serving the entire electrophysiology community from basic to clinical academic researchers, private practitioners, technicians, industry and trainees. HeartRhythm has an impact factor of 4.866 (as of 2016) and ranks 23rd out of 114 cardiovascular medicine journals worldwide by the Institute for Scientific Information, remaining the number one specialty journal in cardiology. It is also the official publication of the Cardiac Electrophysiology Society.