In Vitro Assessment of 3T MRI Effects on Non-3T-Compatible Cardiac Implantable Electronic Devices

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• The safety of cardiac implantable electronic devices (CIEDs) during 3-Tesla (3T) Magnetic Resonance Imaging (MRI) is not fully established, especially for devices not specifically designed for 3T environments.
• This study experimentally assessed the effects of 3T MRI on both 3T-compatible and non-3T-compatible CIEDs.

Purpose of the Study:

• To experimentally evaluate the safety and performance of various CIEDs when exposed to 3T MRI.
• To identify potential risks and malfunctions associated with 3T MRI in pacemakers and implantable cardioverter-defibrillators (ICDs).

Main Methods:

• Fifty-eight CIEDs (37 pacemakers, 21 ICDs) categorized as 3T MRI-conditional, 1.5-T MRI-conditional, or non-MRI-conditional were tested in a 3T MRI scanner.
• Devices were immersed in saline, connected to leads, and programmed to specific pacing modes with MRI mode ON or OFF.
• Interrogation before and after scanning assessed telemetry integrity, parameter retention, and pacing mode changes.

Main Results:

• The majority of CIEDs completed 3T MRI without significant malfunction or telemetry loss.
• Pacemakers, particularly those with low battery status nearing elective replacement indication (ERI), showed a higher incidence of telemetry failure or parameter reset.
• No reset or telemetry failure was observed in implantable cardioverter-defibrillators (ICDs).

Conclusions:

• While most CIEDs are safe for 3T MRI, pacemakers nearing ERI may present an increased risk of telemetry failure or reset.
• Non-negligible mode switching was observed in pacemakers with the MRI mode turned off.
• Overall, severe electrical malfunctions requiring device replacement were rare, and ICDs demonstrated robust safety during 3T MRI exposure.