The objective of the ProMRI Study is to demonstrate the clinical safety of the ProMRI Pacemaker 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 18 years
• Subject body height greater than 140 cm (4' 7")
• Able and willing to complete MRI testing
• Able to provide written informed consent
• Available for follow-up visit at the study site
• Implanted with a pacemaker system consisting only of an Entovis pacemaker (DR-T, SR-T) and one or two Setrox S 53 or Setrox S 60 pacemaker lead(s). (No leads other than Setrox S (53 or 60 cm) leads may be implanted. This includes lead extensions or abandoned leads in the subject.)
• Pacemaker implanted pectorally
• All pacemaker system components implanted, repositioned, or exchanged at least 5 weeks prior to enrollment
• Underling rhythm identifiable during sensing test
• All pacing thresholds are measureable and are less than or equal to 2.0 V @0.4 ms
• Absence of phrenic nerve stimulation at 4.8V @ 1.0 ms
• Pacing impedance is between 200 and 1500 ohm
• Able and willing to use the Cardio Messenger

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 4.8V @ 1.0 ms
• |pacing threshold at Pre-MRI follow-up - pacing threshold at baseline| ≤ 0.5 V
• All pacing thresholds are measureable and are ≤ 2.0 V @ 0.4 ms
• The pacemaker system has been implanted for at least 6 weeks.
• Subject did not have a pacemaker or lead explant, exchange or reposition in the previous 6 weeks.
• All lead impedances are between 200 and 1500 ohm.
• Battery status is at least 30% of capacity

Exclusion Criteria:

• Enrolled in any other clinical study

• For pacemaker systems that include an atrial lead, subjects with either

  • Persistent atrial arrhythmia (lasting longer than 7 days or requiring cardioversion)
  • Permanent atrial arrhythmia

• Life expectancy of less than three months

• Pregnancy

• Cardiac surgery expected in the next three months

• Implanted with other medical devices that may interact with MRI, such as:

  • abandoned pacemaker/ICD leads
  • lead extensions
  • mechanical valves
  • other active medical devices
  • non-MRI compatible devices
  • other metallic artifacts/components in body that may interact with MRI

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