Strategies for the safe magnetic resonance imaging of pacemaker-dependent patients.
OBJECTIVE
To determine if strategies used to safely scan nonpacemaker-dependent patients could be applied to facilitate safe MRI of pacemaker-dependent patients.


METHODS
Ten pacemaker-dependent patients underwent a total of 11 MRI scans of the head and neck. Screening, reprogramming VOO or DOO at 60 ppm, and monitoring strategies were used to facilitate MRI. A transmit-receive coil was used and MRI pulse sequences were modified to limit the whole-body specific absorption rate (SAR).


RESULTS
All scans proceeded uneventfully. No difficulties in post-MRI telemetry or interrogation were seen and no post-MRI programming changes were noted. No patient experienced arrhythmia or symptoms during or immediately after MRI. Battery status remained unchanged. No patient experienced post-MRI change in sensing thresholds. Three patients showed no change in the atrial or ventricular pacing thresholds when the pre-MRI values were compared to the immediate post-MRI values and the 3-month follow-up values. All other patients showed a rise or fall of 0.5 V in their chamber threshold values when the pre-MRI, post-MRI, and 3-month follow-up values were compared. More patients showed a fall in their pacing thresholds than a rise post-MRI.


CONCLUSIONS
While clearly a higher risk group, like nonpacemaker-dependent patients, MRI might be performed in pacemaker-dependent patients if appropriate pacemaker reprogramming, patient monitoring, and MRI scanning techniques are implemented.
Gimbel
J Rod
JR
Park West Hospital, Knoxville, Tennessee, USA. gimbeljr@ix.netcom.com
Bailey
Shane M
SM
Tchou
Patrick J
PJ
Ruggieri
Paul M
PM
Wilkoff
Bruce L
BL
D006801:Humans; D008279:Magnetic Resonance Imaging; D010138:Pacemaker, Artificial; D012449:Safety