MRI Safety and Implanted Cardiac Devices
Millions of Americans have pacemakers, defibrillators and other implanted cardiac devices (ICDs) that stabilize their heart rhythms and improve the functioning of their hearts. These devices can prolong life and enhance quality of life, and technological advances are improving them. There is one significant downside, however, to having an implanted cardiac device: it has been standard medical practice to prohibit people with them from having magnetic resonance imaging, or MRI, diagnostic studies.
The concern has been that the magnetic field generated by the MRI could disrupt the functioning of ICDs, causing arrhythmias, or that the wiring within the ICDs could become overheated and cause shock or tissue injury. It’s a dilemma, because MRIs are extremely useful diagnostic imaging tools, and at some point, nearly everyone needs to have one.
It’s not an unwarranted fear, says Christopher E. Pray, M.D., an expert in cardiothoracic imaging who has recently joined the staff of St. Clair Hospital’s Cardiology Department, practicing with South Hills Cardiology Associates. “There have been incidents where pacemakers malfunctioned during MRI. New developments will change this in the future: the ICDs that we are implanting now are mostly MRI-compatible, and new studies show that non-chest MRIs can be done without adverse outcomes for people with ICDs, under certain conditions. But it’s premature to view this as a major shift; we need more research, with larger groups of patients.”
Dr. Pray says that MRIs are enormously informative imaging studies that should be available to all patients. “In my field, cardiac MRI has been revolutionary. Every day, I do chemical stress tests in the MRI scanner that enable us to see blockages with great accuracy, enabling us to diagnose and manage patients very well.”
Dr. Pray practices with South Hills Cardiology Associates, Bethel Park. He can be reached at 412.942.7900.