Al-Sabagh Kifah Hekmat, Christensen Britta Ege, Thøgersen Anna Margrethe, Petersen Helen Høgh, Videbaek Regitze, Pehrson Steen, Chen Xu, Thomsen Carsten, Svendsen Jesper Hastrup
Kardiologisk Klinik B, Hjertecentret, Rigshospitalet, 2100 København Ø, Denmark.
Ugeskr Laeger. 2010 Jun 7;172(23):1740-4.
The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI examination.
During a period of nine years we have included 65 patients with cardiac devices (60 pacemakers and five ICDs) who underwent a total of 73 MRI examinations at 1.5 T. All pacemakers were reprogrammed before MRI to asynchronous mode to avoid MRI-induced inhibition or to sense only mode to avoid MRI-induced competitive pacing and potential pro-arrhythmia. All devices were interrogated immediately before and after the MRI examination, which included measurement of sensitivity, pacing capture threshold (PCT) and lead impedance.
MRI examinations were completed safely in 63 patients. Inhibition of pacemaker output was observed in one patient and induction of ventricular fibrillation was observed in another with ICD. A significant increase in PCT was rare and only detected in 1% of all electrodes.
MRI can be performed safely in patients with pacemakers with an acceptable risk-benefit ratio, while MRI of patients with ICDs must still be considered an experimental procedure.
心脏植入式设备的存在被认为是磁共振成像（MRI）的绝对禁忌证。本研究的目的是评估在有MRI检查迫切临床需求的心脏起搏器和植入式心脏除颤器（ICD）患者中进行MRI检查的安全性。
在九年的时间里，我们纳入了65例有心脏设备的患者（60例起搏器和5例ICD），他们在1.5T磁场下共接受了73次MRI检查。所有起搏器在MRI检查前均重新编程为非同步模式以避免MRI诱导的抑制，或仅设置为感知模式以避免MRI诱导的竞争性起搏和潜在的心律失常。在MRI检查前后立即对所有设备进行问询，包括测量灵敏度、起搏夺获阈值（PCT）和导线阻抗。
63例患者的MRI检查安全完成。1例患者出现起搏器输出抑制，另1例ICD患者出现室颤。PCT显著增加的情况很少见，仅在所有电极的1%中检测到。
对于起搏器患者，在可接受的风险效益比下，MRI检查可安全进行，而ICD患者的MRI检查仍应被视为一种实验性操作。
