Author + information
- Edward T. Martin, MD, FACC, FACP, FAHA⁎ ( and )
- James A. Coman, MD, FACC
- ↵⁎Cardiovascular MRI Center, Oklahoma Heart Institute, 9228 South Mingo Road, Tulsa, OK 74133
We thank Dr. Sommer and colleagues for their interest in our work (1). We agree that the magnet mode of the pacemaker is not always maintained during magnetic resonance imaging (MRI). We have in fact observed this phenomenon during our experience. This phenomenon is related to the position of the pulse generator relative to the isocenter of the magnetic field. However, this does not alter our recommendations for imaging these patients.
Their statement regarding the possibility of an open reed switch leading to false inhibition and/or false triggering is valid. However, it was for this reason that pacemaker-dependent patients were excluded from our study. We were also concerned about thermogenic damage at the lead-tissue interface with subsequent loss of capture, which would also be detrimental in pacemaker-dependent patients. Finally, we did not alter pacemaker sensing, because in our experience over-sensing on the atrial channel occurs extremely infrequently.
Pacemaker-dependent patients can likely undergo MRI as long as sensing is disabled. However, the possibility of thermogenic damage and loss of capture cannot be overstated.
- American College of Cardiology Foundation