[Safety of magnetic resonance imaging in patients with pacemaker and implantable defibrillator].
BACKGROUND
The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI examination.


METHODS
During a period of nine years we have included 65 patients with cardiac devices (60 pacemakers and five ICDs) who underwent a total of 73 MRI examinations at 1.5 T. All pacemakers were reprogrammed before MRI to asynchronous mode to avoid MRI-induced inhibition or to sense only mode to avoid MRI-induced competitive pacing and potential pro-arrhythmia. All devices were interrogated immediately before and after the MRI examination, which included measurement of sensitivity, pacing capture threshold (PCT) and lead impedance.


RESULTS
MRI examinations were completed safely in 63 patients. Inhibition of pacemaker output was observed in one patient and induction of ventricular fibrillation was observed in another with ICD. A significant increase in PCT was rare and only detected in 1% of all electrodes.


CONCLUSIONS
MRI can be performed safely in patients with pacemakers with an acceptable risk-benefit ratio, while MRI of patients with ICDs must still be considered an experimental procedure.
Al-Sabagh
Kifah Hekmat
KH
Kardiologisk Klinik B, Hjertecentret, Rigshospitalet, 2100 København Ø, Denmark. kifahalsabagh604@hotmail.com
Christensen
Britta Ege
BE
Thøgersen
Anna Margrethe
AM
Petersen
Helen Høgh
HH
Videbaek
Regitze
R
Pehrson
Steen
S
Chen
Xu
X
Thomsen
Carsten
C
Svendsen
Jesper Hastrup
JH
D000075202:Contraindications; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004869:Equipment Safety; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008297:Male; D010138:Pacemaker, Artificial / Q000009:adverse effects