Burke Peter Thomas, Ghanbari Hamid, Alexander Patrick B, Shaw Michael K, Daccarett Marcos, Machado Christian
Providence Heart Institute, Providence Hospital, 16001 W. Nine Mile Rd., Southfield, MI 48075, USA.
J Interv Card Electrophysiol. 2010 Jun;28(1):59-66. doi: 10.1007/s10840-009-9463-y. Epub 2010 Jan 29.
Magnetic resonance imaging (MRI) in patients with Cardiovascular Implantable Electronic Devices (CIED) has not been approved by the Food and Drug Administration. Recent data suggests MRI as a relative rather than absolute contraindication in CIED patients. Recently, the American Heart Association has recommended defibrillation threshold testing (DFTT) in implantable cardioverter defibrillator (ICD) patients undergoing MRI. We evaluated the feasibility and safety of a protocol for MRI in CIED patients, incorporating the new recommendations on DFTT.
Consecutive patients with CIED undergoing MRI were included. The protocol consisted of continuous monitoring during imaging, device interrogation pre- and post-MRI, reprogramming of the pacemaker to an asynchronous mode in pacemaker-dependent (PMD) patients and a non-tracking/sensing mode for non-PMD patients. All tachyarrhythmia therapies were disabled. Devices were interrogated for lead impedance, battery life, pacing, and sensing thresholds. All patients with ICD underwent DFTT/defibrillator safety margin testing (DSMT) post-MRI.
A total of 92 MRI's at 1.5 Tesla were performed in 38 patients. A total of 13 PMD patients, ten ICD patients, four cardiac resynchronization therapy with defibrillator (CRT-D) patients, and 11 non-PMD patients were scanned from four major manufacturers. No device circuitry damage, programming alterations, inappropriate shocks, failure to pace, or changes in sensing, pacing, or defibrillator thresholds were found on single or multiple MRI sessions.
Our protocol for MRI in CIED patients appears safe, feasible, and reproducible. This is irrespective of the type of CIED, pacemaker dependancy or multiple 24-h scanning sessions. Our protocol addresses early detection of potential complications and establishes a response system for potential device-related complications. Our observation suggests that routine DFTT/DSMT post-MRI may not be necessary.
心血管植入式电子设备（CIED）患者的磁共振成像（MRI）尚未获得美国食品药品监督管理局的批准。近期数据表明，MRI对CIED患者而言是相对禁忌而非绝对禁忌。最近，美国心脏协会建议对接受MRI检查的植入式心律转复除颤器（ICD）患者进行除颤阈值测试（DFTT）。我们评估了一项针对CIED患者的MRI方案的可行性和安全性，该方案纳入了关于DFTT的新建议。
纳入连续接受MRI检查的CIED患者。该方案包括成像期间的持续监测、MRI前后的设备问询、将起搏器依赖（PMD）患者的起搏器重新编程为异步模式以及非PMD患者的非跟踪/感知模式。所有快速心律失常治疗均停用。对设备进行导线阻抗、电池寿命、起搏和感知阈值的问询。所有ICD患者在MRI后均接受DFTT/除颤器安全边际测试（DSMT）。
38例患者共进行了92次1.5特斯拉的MRI检查。从四个主要制造商处扫描了总共13例PMD患者、10例ICD患者、4例心脏再同步治疗除颤器（CRT-D）患者和11例非PMD患者。在单次或多次MRI检查中，未发现设备电路损坏、编程改变、不适当电击、起搏失败或感知、起搏或除颤器阈值变化。
我们针对CIED患者的MRI方案似乎是安全、可行且可重复的。这与CIED的类型、起搏器依赖情况或多次24小时扫描检查无关。我们的方案可早期发现潜在并发症，并建立针对潜在设备相关并发症的应对系统。我们的观察表明，MRI后常规进行DFTT/DSMT可能没有必要。
