When programmed to On, MRI SureScan mode disables arrhythmia detection, arrhythmia and CRT therapies, Magnet mode, and all user-defined diagnostics. Before performing an MRI scan, refer to the SureScan pacing, defibrillator, or CRT system MRI technical manuals for important information about procedures and MRI-specific warnings and precautions.

In transvenous pacemaker systems; to program MRI SureScan to On, go to Params -> Additional Features.

In the Micra™ Transcatheter Pacing Systems (TPS); to program MRI SureScan mode to On, go to the Parameters screen.

Under the MRI SureScan field, the MRI SureScan Checklist appears as shown on the screen below. Read the checklist carefully as it may vary depending upon the device. Select the check box in the upper-left corner if all items on the MRI SureScan Checklist are satisfied for the patient. The MRI SureScan Checklist may be printed if desired.

Select OK at the bottom of the MRI SureScan Checklist and the MRI SureScan window appears. Programming MRI SureScan mode to On, allows for programming of an appropriate MRI SureScan pacing mode and MRI SureScan pacing rate as shown below. For patients who require pacing support, program the device to an asynchronous pacing mode (DOO, AOO, VOO for dual chamber (DR) devices and VOO for single chamber (SR) devices). A pacing rate must be selected for these pacing modes to avoid competitive pacing during the operation of MRI SureScan mode. For patients who do not require pacing support, program the device to the non-pacing mode (ODO for DR devices and OVO for SR devices) and a pacing rate is not required.

Micra TPS: MRI SureScan mode programming screen

On the Micra programming screen above, notice the Timeout indicator towards the top of the MRI SureScan page. The device automatically programs the MRI SureScan mode to Off after the indicated time (24 hours). The SureScan Timeout period of 24 hours ensures that the device will not remain in SureScan mode for an overly long period of time after the scan. However, once MR scanning is complete and the patient is in a safe area away from the magnet, interrogate the device and turn MRI SureScan mode to Off, to restore permanent settings.

Transvenous pacemaker systems: MRI SureScan 2090 Programmer screen

Note:  Azure also have the 24 hour MRI SureScan Timeout feature, similar to Micra TPS

ICD: MRI SureScan mode 2090 Programmer screen

CareLink SmartSync™ Device Manager for Cobalt™ and Crome™ ICDs

On the ICD programming screens above, and the CRT programming screen below, notice the Timeout indicator towards the top of the MRI SureScan page. In both ICD and CRT MRI systems, the device automatically programs the MRI SureScan mode to Off, 6 hours after it was programmed to On. This 6-hour timeout period is provided to protect ICD patients from prolonged exposure to spontaneous tachyarrhythmia, and to minimize the amount of time that CRT patients do not receive CRT support. However, once MR scanning is complete and the patient is in a safe area away from the magnet, interrogate the device and turn MRI SureScan mode to Off, to restore permanent settings, detections and therapies, to ensure patient safety.

CRT: MRI SureScan mode 2090 Programmer screen

Additionally, on the CRT programming screen above, notice that when MRI SureScan is programmed to On, V Pacing is RV only. Patients with certain CRT systems will not receive CRT support while MRI SureScan is programmed to On. This lack of CRT pacing may cause dizziness or shortness of breath. Be sure to program MRI SureScan to Off as soon as the MRI scan is complete. Cobalt™ and Crome™ ICD and CRT-D devices have the option of bi-ventricular pacing when MRI SureScan is programmed to On as long as the permanent programmed LV pacing vector does not include the RV coil. 

2090 Programmer screen

CareLink SmartSync™ Device Manager

When MRI SureScan mode is programmed to On, the message, "All Off" appears on the Device Status line to indicate that all detections and therapy features are suspended.

Considerations:

• When MRI SureScan is programmed to On, the device does not do the following:
  • Detect atrial or ventricular tachyarrhythmias or PVCs
  • Deliver atrial or ventricular tachyarrhythmia therapies
  • Initiate asynchronous, fixed-rate bradycardia pacing in the presence of a magnet (pacemaker only)
• When MRI SureScan is programmed to On:
  • All device diagnostic measurements, data collection and counters are suspended.
  • Bradyarrhythmia pacing therapy is provided when an asynchronous pacing mode (DOO, AOO, VOO) is selected for MRI SureScan operation.
  • When DOO mode is selected, the device automatically sets the PAV to either the permanently programmed PAV interval or 110 ms, whichever is less. However, if the permanently programmed PAV is less than 50 ms, the device automatically sets the PAV to 50 ms when MRI SureScan mode is programmed On.
  • When the pacing mode is DOO, AOO, or VOO, the device may automatically set the amplitude and pulse width values. If the permanently programmed RA Amplitude or RV Amplitude is less than 5.0 V, the amplitude is set to 5.0 V. If the permanently programmed RA Pulse Width or RV Pulse Width is less than 1.0 ms, the pulse width is set to 1.0 ms. In Micra TPS, the RV Amplitude is increased by 0.5 V. 
  • In transvenous pacemakers, if the battery voltage falls below the RRT, the normal RRT indication may not be displayed. If the feature is left on indefinitely, the patient will have no indication that the device has reached RRT.

A complete SureScan pacing, ICD or CRT system is required for use in the MRI environment. Any other combination may result in a hazard to the patient during an MRI scan. To verify that components are part of a SureScan system, visit www.mrisurescan.com. The SureScan feature must be programmed to On prior to scanning a patient according to the specified conditions for use.

• SureScan transvenous pacing, ICD and CRT-D systems:
  • No implanted lead extenders, lead adaptors, or abandoned leads
  • No broken leads or leads with intermittent electrical contact, as confirmed by lead impedance history.
  • The SureScan system is implanted in the left or right pectoral region
  • For pacemaker-dependent patients, it is not recommended to perform an MRI scan if the right ventricular (RV) lead pacing capture threshold is greater than 2.0 V @ 0.4 ms. A higher pacing capture threshold may indicate an issue with the implanted lead.
  • The SureScan device is operating within the projected service life
  • No diaphragmatic stimulation is present at a pacing output of 5.0 V and a pulse width of 1.0 ms in patients whose device will be programmed to an asynchronous pacing mode when MRI SureScan is programmed On.

• Tranvenous Pacemaker specific requirements:
  • Pace polarity parameters set to Bipolar for programming MRI SureScan to On (Advisa MRI only).
  • Lead impedance value of ≥ 200 Ω and ≤ 1500 Ω or ≤ 3000 Ω for Azure MRI pacemakers.
  • It is not recommended to perform an MRI scan if the RV pacing capture threshold is greater than 2.0 V at a pulse width of 0.4 ms for pacemaker dependent patients.  A higher pacing capture threshold may indicate an issue with the implanted lead.
  • Revo MRI patients must have pacing capture thresholds of ≤ 2.0 V at a pulse width of 0.4 ms and a SureScan pacing system that has been implanted for a minimum of 6 weeks.
• CRT-P specific requirements: 
  • For CRT-P systems atrial and RV pace polarities must be set to bipolar for programming the MRI SureScan mode to On. 
  • If a lead impedance measurement value is < 200 Ω or > 3000 Ω, or unavailable, the software prevents the MRI SureScan feature from being initiated. 

• No abandoned leads are present.
• For patients who have multiple MR Conditional devices present, the MR labeling conditions for all implanted devices are satisfied.
• The active SureScan™ device is operating within the projected service life.
• Pacing amplitude is ≤ 4.5 V at the programmed pulse width.
• No diaphragmatic stimulation is observed when MRI SureScan is programmed to On.
• The SureScan device that is beyond its projected service life is programmed to Device Off.

• Horizontal field, cylindrical bore, clinical system for hydrogen proton imaging
• Static magnetic field of one of the following strengths (See details in table below):
  • 1.5T
  • 3T
• Maximum spatial gradient of ≤ 20 T/m (2000 Gauss/cm)
• Gradient systems with maximum gradient slew rate performance per axis of ≤ 200 T/m/s