Magnetic Resonance Imaging in Patients with Implantable Cardioverter-Defibrillators: The Walls Are Crumbling

Magnetic resonance imaging is not recommended for patients with pacemakers or implantable cardioverter-defibrillators. Occasionally, the inability to perform MRI can seriously affect diagnosis, management decisions, or both. Animal studies and limited human case series suggest that with current technology, MRIs might not be absolutely contraindicated in patients with pacemakers or even in those with more-complex ICDs.

In a prospective, carefully conducted trial, 18 non–pacemaker-dependent patients with ICDs underwent MRI with a 1.5-T limit. ICD therapy, but not detection, was turned off. Pacemaker upper rate limits were programmed as low as possible to prevent pacing due to radiofrequency oversensing. All ICDs were interrogated before and af…