ProMRI

To receive approval for MRI usage, a new set of requirements were added to the design and testing of the cardiac device system. The cardiac devices and the leads are tested individually and as a combined system, as approval is only given for the specific combinations of lead(s) and devices.

Examples of additional requirements are:

• No significant change in temperature of the lead(s) in the MRI environment. The leads can act as an antenna and dissipate the energy of the radio frequency field as temperature rise to the tip of the lead.
• Ensure optimal therapy through specific MRI modes of the devices. The MR environment may lead to inadequate sensing of the heart rhythm or unintentional pacing.
• Withstand electromagnetic interference. The strong static, gradient and RF fields present in the MR environment may affect the electrical operation of the device or its software.

MR imaging is the preferred diagnostic modality for many soft tissue, sometimes life threatening conditions. As many patients with a cardiac device also have other comorbidities, up to 75% of these patients will need an MRI in their lifetime.⁴ 

In 2012, the overall number of MRI scans in the US reached 30.2 million procedures.5 MRI volumes will continue to be driven by growth in brain, musculoskeletal, and spine applications, in addition to newer procedures like cardiac MRI.

The need for MRI scanning is highest in the age group between 55-80 years, patients in this age group are also more likely to receive a cardiac device. As the demographics in many countries show a population growth of elderly people, an increase in demand of MRI scans with patients implanted with cardiac devices is expected as well.

The growing number of patients with an implanted cardiac device and the increased use of MRI to diagnose diseases like cancer or stroke will collide and result in more and more patients missing out on MRI scans. For the US in 2004 alone, it was estimated that 200,000 device patients missed out on MRI scans.⁶ To counteract this problem, BIOTRONIK continuously strives to eliminate these barriers by introducing MR conditional pacemakers, leads and other cardiac devices.

Make sure the combination of the device and its leads are approved as MR conditional. As the approval status may vary between countries, there might be differences in the MRI conditions for the implanted system between certain countries.

• To check if the implanted system is MR conditional visit the ProMRI®System Check Website
• For conditions and combinations of ProMRI device systems, also check the ProMRI manual, available on the BIOTRONIK manual library
• To configure an MR conditional system for implant visit the ProMRI®Configurator

For patients with a cardiac device, MRI has been a contraindication for many years. Today BIOTRONIK offers in more than 100 countries, a comprehensive portfolio of MR conditional cardiac devices and leads which are approved for usage in the MR environment. In order to allow the patient to undergo an MRI scan, specific conditions have to be met. To perform the MR procedure, the radiologist must make sure that these specific ProMRI conditions are adhered to.

The sharing of information between cardiologist and radiologist is also important to make sure the MRI scanning takes place within the boundaries of the ProMRI conditions. Here you can find the information you need to scan patients with a BIOTRONIK MR conditional cardiac monitor, pacemaker, ICD or CRT system.

Before the patient can undergo the MRI scan, the patient first needs to have a follow up by a cardiologist. During this follow up, the cardiologist will check if the system is approved as MR conditional and program the device to the MRI mode. The MRI mode is specifically designed to allow MRI scanning, but offers limited device therapy. For instance the tachy arrhythmia therapy in ICD devices is switched to off. The timing of the device programming by the cardiologist and MRI scanning should therefore be carefully planned.

BIOTRONIK devices may have the MRI AutoDetect feature. In this device a built-in sensor detects the MR environment and automatically programs the device in the preset MRI mode. To activate the sensor and program the MRI mode, a visit to the cardiologist prior to the MRI is still required.

The Patient ID card will indicate if the cardiac system is MR conditional.

Note: If all specific conditions of the scanning procedure are met, the device system can be used in the MR environment.

Patients with an MR conditional cardiac monitor, pacemaker, ICD or CRT system the following measures must be taken before, during and after the scan:

1. Patient visits cardiologist prior to an MRI scan.

2. The cardiologist checks if scanning is allowed and programs the device to a specific MRI setting.

3. The MRI scan is performed according ProMRI conditions by a radiologist.

4a. The cardiologist programs the device to its previous settings and a follow up is being performed.

4b. If the system has the MRI AutoDetect function, programming back to previous settings is done automatically (if the device has Home Monitoring activated, a follow up is being performed via Home Monitoring).

5. Patient continues as usual with regular follow ups.

The MRI scan of a patient having an MRI conditional device, can be distorted by artefacts caused by the device system. The closer the implanted device is near the scanned area, the risk of artefacts increases. In most cases however, the implanted cardiac devices do not limit the clinical diagnostic value of the MRI image.