The objective of the ProMRI Study (Phase B) is to demonstrate the clinical safety of the ProMRI Pacemaker System when used under specific MRI conditions without scan exclusion zone.

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
• 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.