Temporary device malfunction of an MR conditional cardiac resynchronization defibrillator when undergoing MRI without...

Magnetic resonance (MR) imaging (MRI) for patients with implantable cardiac devices is becoming more routine, with the development of MR conditional devices allowing more patients access to the imaging they need. However, for this to be performed safely, strict protocols must be followed necessitating close collaboration between cardiology and radiology departments. We present a case where mandatory device re-programming of a cardiac resynchronization therapy defibrillator device into MRI mode was not performed pre-scan leading to temporary device dysfunction with no clinical consequences.

A 72-year-old man presented to a device clinic for a routine device interrogation. An atrial tachycardia response episode was recorded at the same time as the patient reported having undergone an MRI scan at a local centre. The electrogram demonstrated temporary right ventricular loss of capture with standard output programming, and a short episode of oversensing on the atrial and ventricular channel which was not sustained for long enough to meet tachycardia detection.

We demonstrate two potential electrophysiological effects of MRI on pacemakers, where the device had not been appropriately re-programmed pre-procedure. This illustrates that whilst MRI in patients with implantable cardiac devices is safe, strict protocols must be followed requiring robust multidisciplinary communication.