The objective of the ProMRI Study is to demonstrate the clinical safety of the ProMRI ICD System when used under specific MRI conditions.

Inclusion Criteria:

The following initial inclusion criteria must be met for a subject to be enrolled and considered for the MRI-procedure:

• Age greater than or equal to 18 years
• Able and willing to complete MRI testing
• Able to provide written informed consent
• Available for follow-up visit at the study site
• Implanted with an ICD System consisting only of an Iforia DR-T and Linoxsmart S 65 / Linoxsmart SD 65/18 with Setrox S 53 atrial lead or Iforia VR-T DX and Linoxsmart S DX 65/15 or Linoxsmart S DX 65/17.
• ICD implanted pectorally
• All ICD system components implanted, repositioned, or exchanged at least 5 weeks prior to enrollment
• Underlying rhythm identifiable during sensing test
• All pacing thresholds are measureable and are less than or equal to 2.0 V @ 0.4 ms (Criterion does not apply to atrial pacing threshold for subjects with an Iforia DR-T that have AF and are permanently programmed to VVI and for subjects with an Iforia VR-T DX)
• Ventricular sensing is measurable and >6.5mV
• Absence of phrenic nerve stimulation at 5.0V and 1.0 ms
• Pacing impedance is between 200 and 1500 ohm
• Shock Impedance is between 30 and 90 ohm
• Able and willing to use the CardioMessenger II

At the pre-MRI procedure, the following procedure-related criteria must be met for the subject to undergo the MRI scan:

• Absence of phrenic nerve stimulation at 5.0V @ 1.0 ms
• |pacing threshold at Pre-MRI follow-up - pacing threshold at baseline| ≤ 0.5 V (ICD Lead Only)
• All pacing thresholds are measureable and are less than or equal to 2.0 V @ 0.4 ms (Criterion does not apply to atrial pacing threshold for subjects with an Iforia DR-T that have AF and are permanently programmed to VVI and for subjects with an Iforia VR-T DX.)
• Ventricular sensing is measurable and >6.5mV
• The ICD system has been implanted for at least six weeks.
• Subject did not have an ICD or lead explant, exchange or reposition in the previous 6 weeks.
• All lead pacing impedances are between 200 and 1500 ohm
• Shock impedance is between 30 and 90 ohm
• Battery status is at least 30% of capacity

The patients selected for participation should be from the investigators' general patient population according to the inclusion and exclusion criteria.