Introduction
Patient selection
Practical issues around the MRI scan
Technical specification of magnetic resonance imaging |
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For MRI-conditional devices follow manufacturer’s instructions for scan |
For non-MRI-conditional devices: |
– 1.5 T MRI should be preferred |
– Gradient slew rate should not exceed 200 T/m/s |
– Dorsal patient position |
– Imaging landmark near the device (thorax) should be avoided |
– Local transmit coils should be avoided |
– SAR and scan time should be limited |
Emergency equipment/external defibrillator as well as a device programmer should be present during the MRI |
Continuous patient monitoring (electrocardiography/pulse oximetry) during the MRI should be performed |
In pacemaker-dependent patients: asynchronous mode (VOO/DOO) with HF of 80–90/min with high output, RV-only pacing in biventricular devices |
In non-pacemaker-dependent patients:
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– Resting heart rate >50/min: VVI or DDI 30–40/min |
– Resting heart rate <50/min: consider VOO/DOO 80–90/min with high output |
– RV-only pacing in CRT patients |
Deactivate additional features:
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– Rate response mode |
– Anti-tachycardia therapies (including anti-tachycardia pacing and shocks)—ICD only |
– LV-triggered pacing (ventricular sense response)—biventricular devices only |
– Anti-pacemaker-mediated tachycardia pacing (PMT algorithms) |
– PVC-triggered pacing response |
– PAC-triggered pacing response |
– Atrial fibrillation therapies (rate smoothing, overdrive pacing, conducted atrial fibrillation response) |
– Hysteresis pacing |
– Magnet response (if the option exists) |
– Noise response |
Scenario | Possible reasons |
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Asystole | Device malfunction in asynchronous mode ‘Power-on reset’ with pacing inhibition by noise True bradycardia in non-pacemaker dependent patients in inhibitory mode |
Ventricular fibrillation/tachycardia | R-on-T phenomenon in asynchronous pacing mode True arrhythmia |
Sudden rise in heart rate | ‘Power-on reset’ in inhibitory mode leading to pacing True endogenous tachycardia |
Sudden drop in heart rate | ‘Power-on reset’ in asynchronous mode True endogenous bradycardia in inhibitory mode |