MRI Safety in Patients with Pacemakers

Device-Specific Considerations

The European Society of Cardiology recommends that MRI-conditional pacemaker systems can be safely scanned at 1.5 Tesla following manufacturer instructions 1, 2
MRI-conditional pacemakers have automatic programming features that switch modes during MRI without manual intervention, as recommended by the European Heart Journal 2
The American Heart Association suggests that leadless pacemakers are MRI-conditional at both 1.5T and 3.0T and carry substantially lower risks due to absence of transvenous leads, although this fact is from a less preferred source 3, 4
The device must be implanted for at least 6 weeks to ensure lead maturation and position stabilization, as stated by the European Heart Journal 1, 2
Conventional pacemakers can be scanned at 1.5 Tesla with a low risk of complications when specific precautions are taken, with a Class IIb recommendation from the European Heart Journal 1, 2

The European Society of Cardiology recommends verifying the specific device model and MRI-conditional status with manufacturer specifications, although this fact is from a less preferred source 3, 4
Patients with leads implanted less than 6 weeks ago should be excluded due to the risk of dislodgement, as recommended by the European Heart Journal 1, 2
Patients with epicardial or abandoned leads should be excluded due to the risk of heating, as stated by the European Heart Journal 1, 2
Device interrogation should be performed to record baseline parameters, including impedance, capture threshold, sensing amplitude, and battery voltage, as recommended by the European Heart Journal and the American Heart Association 1, 2, 4

Continuous ECG monitoring throughout the entire procedure by qualified personnel is recommended by the American Society of Anesthesiologists 7, 4
Peripheral pulse monitoring using pulse oximetry, arterial line, or manual palpation is recommended by the American Society of Anesthesiologists 7
Temporary pacing and defibrillation equipment should be immediately available, as recommended by the American Society of Anesthesiologists 7
MRI scanning should be limited to 1.5 Tesla field strength, with no data existing for higher field strengths even with MRI-conditional devices, as stated by the European Heart Journal 1, 2

The device should be re-interrogated immediately after MRI and compared to baseline parameters, as recommended by the European Heart Journal and the American Heart Association 1, 2, 4
Original programming settings should be restored, as recommended by the European Heart Journal 1, 2
Cardiac rate and rhythm should be monitored with backup equipment available throughout the immediate postoperative period, as recommended by the American Society of Anesthesiologists 7

Historical reports of sudden death exist in patients scanned without proper protocols, as reported by Anaesthesia 5, 6
Magnetic field strengths exceeding 0.5 mT (5 Gauss) can cause fatal pacemaker malfunction if precautions are not followed, as reported by Anaesthesia 5, 6
Consultation with an electrophysiology specialist is warranted for all cases, as recommended by the European Heart Journal 1, 2
When MRI is necessary for clinical management of serious diseases, the benefit may outweigh the risk, but alternative imaging techniques should be considered first, as recommended by the European Heart Journal 1, 2