Year : 2014  |  Volume : 17  |  Issue : 3  |  Page : 252--254

In response to "Magnets and implantable cardioverter defibrillators: What's the problem?"

Rajnish Kumar 
 Department of Cardiac Anaesthesiology and Critical Care, Heart Hospital, Patna, Bihar, India

Correspondence Address:
Rajnish Kumar
House No. 28-I/1, West Anandpuri, Boring Canal Road, Patna - 800 001, Bihar

How to cite this article:
Kumar R. In response to "Magnets and implantable cardioverter defibrillators: What's the problem?".Ann Card Anaesth 2014;17:252-254

How to cite this URL:
Kumar R. In response to "Magnets and implantable cardioverter defibrillators: What's the problem?". Ann Card Anaesth [serial online] 2014 [cited 2020 Jul 4 ];17:252-254
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Full Text

The Editor,

The article "magnets and implantable cardioverter defibrillators (ICD): What's the problem?" is interesting. [1] The case report highlight the drawbacks of using a magnet to suspend ICD therapy and illustrate the factors associated with electromagnetic interference (EMI). The authors note that failure to follow published expert advisory concerning ICDs may lead to adverse events. [1] The Heart Rhythm Society (HRS)/American Society of Anesthesiologists state that important informations should be given to the cardiovascular implantable electronic device (CIED) team, such that they can provide specific recommendations to the procedural team, regarding the perioperative management of the patient's CIED. It is not clearly mentioned in this case report that procedural team gave the specific information to the CIED team or whether CIED team ask about these information? [2],[3] However, patients' cardiologist had cleared him for the surgery without any recommendations regarding perioperative ICD management. St. Jude representative, the ICD provider, also provided insufficient information to the procedural team by not advising proper magnet location over the device to disable its anti-tachycardia therapy. [1]

The authors' state the surgeons initially declined to use a bipolar electrosurgical unit since the ICD was supposedly inactive by magnet placement. If the pulse generators have a specific magnet-sensitive switch then they activate a predefined circuit or program subroutine. The application of an appropriately positioned magnet over an ICD will suspend tachyarrhythmia detection and treatment except in devices where this function is specifically programmed off. But, the magnet will not affect the pacing capability of the ICD. However, EMI may inhibit the pacemaker function of the device and cause asystole in a fully pacemaker dependent patient. Thus, pacemaker reprogramming to an asynchronous mode must be considered in an ICD patient who are pacemaker dependent. [4],[5]

Pacemakers and defibrillators are sensitive to electric and magnetic artifacts. ICDs may improperly detect electrocautery artifacts as a repetitive depolarization of the heart chamber where the electrode is located. This "tachycardia" can prompt the delivery of an inappropriate shock and possibly, happened in this case. For safe and better patient outcome, all members of CIED and procedural team must respect and follow the published expert advisory, at every step in the perioperative period. [2],[4],[5]

The principal advantage of the magnet is that it can be quickly placed and removed. The site of magnet placement is important since a poorly positioned magnet may not produce the desired effect, which occurred in the reported case. The application of the magnet is not fully reliable because among various manufactures there is no standardization regarding site and response to magnet placement. Further all CIEDs' do not come with an indicator to guide appropriate placement. [2],[6] The Smart Magnet is a novel idea, it has not been widely used due to its manufacturer specificity. In future, the clinical magnets shall not only be "smart", but also be "universal", making possible their use on all CIED. This shall be facilitated by introducing a universal microchip in the CIEDs capable of communicating with the magnet. In addition, the smart-universal magnet shall come with an indicator that provides simple warnings (auditory or visual) when CIED has recognized magnet meaning electrical reset of the CIED occurred. [6] Discussions about this issue are under way at the Association for the Advancement of Medical Instrumentation Washington, DC. [7],[8]

Perioperative management of patients with CIED is becoming complicated day by day as the indications, complexity and manufactures of CIED continues to grow. We anesthesiologist should educate, train, and certify ourselves in the field of perioperative CIED management. Anesthesiologists are, by nature, pioneers in cross-specialty training. About 20 years back, the first intraoperative use of transesophageal echocardiography (TEE) was published. Today, many anesthesiologists are certified in perioperative TEE. Similar certification in the pacing environment exists under the auspices of the HRS. Established in 1985, The International Board of Heart Rhythm Examiners is a self-governing, credentialing organization of the HRS that provides competency certification in cardiac rhythm device therapy and cardiac electrophysiology for physicians and allied professionals ( [7]


1Rodriguez-Blanco YF, Souki F, Tamayo E, Candiotti K. Magnets and implantable cardioverter defibrillators: What′s the problem? Ann Card Anaesth 2013;16:54-7.
2Crossley GH, Poole JE, Rozner MA, Asirvatham SJ, Cheng A, Chung MK, et al. The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus Statement on the perioperative management of patients with implantable defibrillators, pacemakers and arrhythmia monitors: Facilities and patient management this document was developed as a joint project with the American Society of Anesthesiologists (ASA), and in collaboration with the American Heart Association (AHA), and the Society of Thoracic Surgeons (STS). Heart Rhythm 2011;8:1114-54.
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