The Relationship between MRI Radiofrequency Energy and Function of Nonconditional Implanted Cardiac Devices: A...

Area of Science:

• Radiology and Imaging
• Cardiovascular Devices
• Medical Physics

Background:

• Risks of MRI in patients with implanted cardiac devices are attributed to interactions with magnetic fields.
• Understanding these interactions is crucial for patient safety during diagnostic imaging.

Purpose of the Study:

• To investigate the relationship between MRI parameters (SAR, dB/dt, energy dose) and changes in cardiac device function.
• To assess the impact of imaging region and device characteristics on device performance post-MRI.

Main Methods:

• Prospective observational cohort study of 1464 patients with implanted cardiac devices undergoing 2028 MRI examinations.
• Collected MRI parameters (SAR, dB/dt, scan duration) and evaluated device function (sensing, impedance, capture threshold) before and after MRI.
• Statistical analysis using generalized estimating equations.

Main Results:

• No association found between radiofrequency energy deposition, dB/dt, or scan duration and changes in most device parameters.
• Thoracic MRI was associated with a slight decrease in battery voltage.
• Right ventricular lead length correlated with reduced sensing and capture thresholds.

Conclusions:

• MRI parameters related to radiofrequency energy exposure did not show significant association with immediate changes in cardiac device and lead parameters.
• Device interrogation before and after MRI is essential due to potential for device reset or parameter changes.
• Specific findings like battery voltage changes and lead length effects warrant continued vigilance.