MRI scanning in persons with pacemakers: Please note that magnetic resonance imaging (MRI) is absolutely contraindicated in pacemaker dependent patients with older generation pacemakers. Following discussion is regarding these older generation pacemakers which are not MRI conditional. For a discussion on MRI conditional pacemakers, please click here.
In those who are not pacemaker dependent, they must have a documented very serious, life threatening or severely quality of life limiting condition requiring MRI scanning before planning an MRI study. The procedure must be approved by attending radiologist and a cardiology consultation is essential to determine pacemaker dependency. Radiologist and cardiologist must work in a coordinated fashion and the study should be conducted only in a major hospital during weekdays and regular business hours when all faculty are available for support. It is preferable to use field strengths of 1.5 Tesla or lesser, though it can lead to slower scans with limited information. The device must have been in place for 4-8 weeks prior to MRI. The pacemaker should be programmed to OFF or sub threshold outputs prior to the procedure. Full device interrogation has to be done prior to and after the MRI scan. Device interrogation should be repeated 3 months after MRI to measure pacing thresholds.
ACLS certified physician has to monitor the patient at the MR-console. Pacemaker programmer should be available at the MR-scanner. Crash cart with an external defibrillator-pacemaker must be present in the MR unit. But it is not feasible to use a defibrillator within the MR room, patient should be quickly shifted out of the room if defibrillation is required.