A study
by Russo et al published in the NEJM
found that MRI scans for patients with older not FDA approved pacemakers and implantable
cardioverter-defibrillators (ICD) are safe even if the scan
focuses on the chest area.
The researchers performed 1000 MRI in which patients had a
pacemaker and in 500 MRI in which patients had an ICD in a 1.5T MRI scanner. No
deaths, lead failures, losses of capture, or ventricular arrhythmias occurred
during MRI. One ICD generator could not be interrogated after MRI and required
immediate replacement; the device had not been appropriately programmed per
protocol before the MRI. Nine of the implants were
disrupted but reset themselves to backup mode.
In all but one instance the effect was temporary.
Neither
MRI performed on chest or in other parts of the body produced significant
complications. The concerns of
potential magnetic field–induced cardiac lead heating, which could result in
myocardial thermal injury and/or disrupt pacing properties of the devices were
noted in this study.
The
authors concluded that in their study, device or lead
failure did not occur in any patient who was appropriately screened, and had
the device reprogrammed in accordance with the pre-specified protocol.
