Clinical applications of magnets on cardiac rhythm management devices

Transitioning from 0.5 to 0.9 mT: Protecting against inadvertent activation of magnet mode in active implants

The "5 gauss line" is a phrase that is likely to be familiar to everyone working with MRI, but what is its significance, how was it defined, and what changes are currently in progress? This review explores the history of 5 gauss (0.5 mT) as a threshold for protecting against inadvertently putting cardiac pacemakers, implantable cardioverter defibrillators, and other active implantable medical devices into a "magnet mode." Additionally, it describes the background to the recent change of this threshold to 9 gauss (0.9 mT) in the International Standard IEC 60601-2-33 edition 4.0 that defines basic safety requirements for MRI. Practical implications of this change and some ongoing and emerging issues are also discussed.

Ventricular Fibrillation Simulated Electrocardiogram Artifact by a Deep Brain Stimulator

Deep brain stimulation devices can disrupt cardiac rhythm interpretation by causing electrocardiogram artifact. We report the case of a deep brain stimulating device initiating ventricular fibrillation simulated electrocardiogram artifact in the prehospital setting. Mimicked ventricular fibrillation due to a deep brain stimulator has not been documented, and if unrecognized could influence unwarranted or potentially harmful clinical decisions.

Complications related to pacemakers and other cardiac implantable electronic devices: essentials for internists and emergency physicians

With the aging population, improving technology, and expanding indications for diagnosing and treating arrhythmias and heart failure, many patients are receiving cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable cardioverter defibrillators. Consequently, patients with CIEDs are frequently encountered in the emergency department and in the wards. It is imperative that emergency physicians and internists have a strong foundation on CIEDs and their potential complications. This review aims to help physicians develop a framework in approaching CIEDs and to recognize and manage clinical scenarios that may arise from CIED complications.

Evaluating the magnet response in deep subcutaneous implanted cardioverter defibrillator implants

INTRODUCTION

The manufacturer of subcutaneous implantable cardioverter defibrillators (S-ICDs) acknowledges that 'deep implants' may fail to elicit a magnet response, however, does not define 'deep implant' or recommend a maximum implant depth. This study aims to systematically evaluate the effect of subcutaneous tissue depth and magnet types on evoked magnet response.

METHODS

Sunshine Coast University Hospital's S-ICD cohort underwent magnet response evaluation; where bar and donut magnets were compared and the evoked magnet response was recorded in three separate zones, guided by a template. Ordinal regression (OR) models assessed the relationship between the evoked magnet response and tissue depth (TD), measured via post-implant X-Ray. The patient's ability to hear the magnet response audible tone was recorded.

RESULTS

Patients (n = 39) with measurable TD (n = 30) were analyzed. The bar magnet evoked a magnet response in all zones in 53% of patients, compared with 73% of patients with the donut magnet (p = 0.18). The relationship between bar magnet response and TD showed the odds of an evoked magnet response decreased by 11% every 1 mm increase in TD (OR of 0.89, p < 0.01), whereas the donut magnet decreased by 16% per 1 mm (OR of 0.84, p < 0.01). Directly over the S-ICD was the most effective in evoking magnet response with the bar (85% of patients), and off-centre was most effective for the donut magnet (100%). BMI and Praetorian score were not significantly associated with magnet response. We found 23% of patients were unable to detect the audible tone.

CONCLUSION

We observed a statistically significant association between TD and ability to evoke magnet response. The bar magnet was less reliable than the donut magnet for therapy inhibition in deep implants.

An Unexpected Magnet Response of a Biotronik Pacemaker in Automatic Mode: A Case Report

In patients with cardiovascular implantable electronic devices, asynchronous pacing is necessary for surgeries with a risk of electromagnetic interference. Magnets are often used for asynchronous pacing. In this case report, magnet application to a Biotronik Evia DR-T pacemaker (Biotronik) programmed to a magnet response mode called automatic magnet mode (AUTO) led to a brief period of asynchronous pacing before reverting to prior settings, an unexpected response that was not revealed on the preoperative interrogation report. For Biotronik pacemakers programmed to the AUTO mode, changes in programming are needed for asynchronous pacing.

Effects of medically generated electromagnetic interference from medical devices on cardiac implantable electronic devices: A review

As cardiac implantable electronic devices (CIED) become more prevalent, it is important to acknowledge potential electromagnetic interference (EMI) from other sources, such as internal and external electronic devices and procedures and its effect on these devices. EMI from other sources can potentially inhibit pacing and trigger shocks in permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), respectively. This review analyzes potential EMI amongst CIED and left ventricular assist device, deep brain stimulators, spinal cord stimulators, transcutaneous electrical nerve stimulators, and throughout an array of procedures, such as endoscopy, bronchoscopy, and procedures involving electrocautery. Although there is evidence to support EMI from internal and external devices and during procedures, there is a lack of large multicenter studies, and, as a result, current management guidelines are based primarily on expert opinion and anecdotal experience. We aim to provide a general overview of PPM/ICD function, review documented EMI effect on these devices, and acknowledge current management of CIED interference.

Magnetic field interactions between current consumer electronics and cardiac implantable electronic devices

BACKGROUND

Electronic products, including the iPhone 12, Apple Watch Series 6, and 2nd Generation AirPods, contain magnets to facilitate wireless charging. Permanent magnets may affect CIED magnet mode features by causing pacemakers to pace asynchronously and defibrillators to suspend arrhythmia detection. This study determined if CIEDs are affected by static magnetic fields from commonly used portable electronics (PE) at any distance and intends to reinforce FDA recommendations concerning consumer PE which contain permanent magnets.

METHODS

The maximum magnet field measurement was evaluated by a Gauss meter. The interaction between PE and CIEDs from Boston Scientific and Medtronic were tested ex vivo using a body torso model. The CIED was placed in physiologic saline, and the PE was placed at the surface and at increasing distances of 0.5, 1.0, and 1.5 cm. Interactions were recorded by assessment of magnet mode status.

RESULTS

The iPhone 12 had almost three times the static magnetic field measured at the surface as the iPhone XR, but magnetic field strength decreased dramatically with increasing distance. At the surface of the model, PE triggered magnet mode in all CIEDs. The maximum interaction distance for all combinations of CIEDs and Apple products was 1.5 cm.

CONCLUSIONS

The iPhone 12 produces a stronger static magnetic field than previous iPhone models. Magnets in PE tested will not interact with CIEDs when they are 15 cm from the implanted device. Since no interaction was observed beyond 1.5 cm, it is unlikely that magnet mode activation will occur during most daily activities.

Safety and Efficacy of Magnet Use to Temporarily Inhibit Inappropriate Subcutaneous Implantable Cardioverter Defibrillator Therapy in Emergency Situations: A Case Report

Introduction: The subcutaneous implantable cardioverter defibrillator (S-ICD) represents a major advancement in ICD technology. Inappropriate shocks (IAS) occur in more than 3.1% of the population with S-ICD each year and are usually followed by admission to the emergency department (ED). In this setting, the disabling of IAS is mandatory during a pseudo-electrical storm (ES). This report describes the strategies that can be followed in order to temporarily inhibit IAS in critical care settings with the use of magnets.

Case presentation: An S-ICD was implanted more than 6 weeks prior to presentation in a 68-year-old man with hypertrophic cardiomyopathy. In the ED, the patient experienced 3 IAS in the last hour. A Medtronic magnet was applied to stop IAS, as the specific programmer was not available. The maneuver interrupted the IAS. In order to verify the universal magnetic response of the S-ICD, six different magnets and one smartphone with MagSafe technology were tested. All magnet models suspended arrhythmia detection and IAS, while the smartphone did not cause magnet interferences.

Conclusions: This report demonstrates the safety and efficacy of all clinical magnet models in inhibiting IAS. In case of pseudo-ES, any type of magnet allows ED providers to easily and rapidly disable the functionality of the devices when appropriate.

Interference by Modern Smartphones and Accessories with Cardiac Pacemakers and Defibrillators

Purpose of Review

The risk of cardiac implantable electronic device (CIED) interference from cell phones was previously thought to be low based on older studies. Current generation of smartphones have incorporated more magnets for optimization of wireless charging, attachment of accessories, and convenience functionalities. These magnets have the potential to cause CIEDs to inadvertently revert into magnet mode. The purpose of this review is to summarize recent findings on smartphones and their accessories causing interference on CIEDs.

Recent Findings

Recent reports have demonstrated that the iPhone 12 series and accessories have the capability to cause CIED magnetic interference.

Summary

Current generation of smartphones, smartwatches, wireless headphones, and accessories have the potential to cause CIEDs to revert into magnet mode in both in vivo and ex vivo experiments. The risk of a clinically significant event is unlikely as long as the Food and Drug Administration (FDA) recommendations are followed; keeping smartphones and accessories at least six inches away from CIEDs.

iPhone 12 MagSafe technology and cardiac implantable devices: assessment of the actual risk

Background

Pacemaker (PM) and implantable cardioverter defibrillators (ICD) are equipped with a magnetic sensor activated by external application of magnets to easily manage some functions of these devices. If activated inadvertently or outside a controlled environment and without the supervision of clinical personnel, this magnetic mode introduces a potential risk. In reality, the possibility of a static magnetic field affecting a PM or ICD is remote. However, the presence of the magnet in the iPhone 12 made the possibility of inadvertently activating the magnetic switch of PM and ICD less remote.

Objective

This study investigates the effects of magnetic interference of the iPhone 12 on a large set of cardiac implantable devices representative of the current market and proposes adequate rules of conduct.

Methods

We investigated the risk of the magnetic interference of the iPhone 12 and its MagSafe accessories on a comprehensive set of PMs and ICDs, including the subcutaneous ICD. For the first time, the magnetic interference phenomena were correlated with the magnetic field levels measured all around iPhone 12.

Results

We discovered that the magnets inside iPhone 12 trigger the magnetic mode in the 12 tested devices up to a distance of 1 cm.

Conclusions

Considering the implications related to the activation of the magnetic switch, to date, it is advisable to follow Apple's indications relating to the safety distance of 15 cm, which is widely compatible with the results obtained from this paper and in line with the indications provided by the implantable cardiac device manufacturers.

The perioperative management of small animals with previously implanted pacemakers undergoing anaesthesia

OBJECTIVE

There is little information in the veterinary literature about the perioperative management of small animal patients with previously implanted pacemakers undergoing elective or emergency non-cardiac procedures. The purpose of this article is to review the current literature with regard to human patients, with previously implanted pacemakers, undergoing general anaesthesia. Using this and the current information on pacemakers and anaesthesia in dogs and cats, we provide recommendations for small animal patients in this situation.

DATABASES USED

Google Scholar, PubMed and CAB Abstracts using and interlinking and narrowing the search terms: "dog", "cat", "small animals", "anaesthesia", "pacemaker", "perioperative", "transvenous pacing", "temporary pacing". Scientific reports and human and small animal studies from the reference lists of the retrieved papers were reviewed. In addition, related human and veterinary cardiology and anaesthesia textbooks were also included to create a narrative review of the subject.

CONCLUSIONS

The best perioperative care for these animals comes from a multidisciplinary approach involving the anaesthetist, cardiologist, surgeon and intensive care unit team. When such an approach is not feasible, the anaesthetist should be familiar with pacemaker technology and how to avoid perioperative complications such as electromagnetic interference, lead damage and reprogramming of the device. The preanaesthetic assessment should be thorough. Information regarding the indication for pacemaker placement, complications during the procedure, location, type and programming of the pacemaker should be readily available. The anaesthetic management of these veterinary patients aims to preserve cardiovascular function while avoiding hypotension, and backup pacing should be available during the perioperative period. Further prospective studies are needed to describe the best perioperative care in small animals with a previously implanted pacemaker.

Magnetic field-induced interactions between phones containing magnets and cardiovascular implantable electronic devices: Flip it to be safe?

BACKGROUND

Recent case reports and small studies have reported activation of the magnet-sensitive switches in cardiovascular implantable electronic devices (CIEDs) by the new iPhone 12 series, initiating asynchronous pacing in pacemakers and suspension of antitachycardia therapies in implantable cardioverter-defibrillators (ICDs).

OBJECTIVE

The purpose of this prospective single-center observational study was to quantify the risk of magnetic field interactions of the iPhone 12 with CIEDs.

METHODS

A representative model of each CIED series from all manufacturers was tested ex vivo. Incidence and minimum distance necessary for magnet mode triggering were analyzed in 164 CIED patients with either the front or the back of the phone facing the device. The magnetic field of the iPhone 12 was analyzed using a 3-axis Hall probe.

RESULTS

Ex vivo, magnetic interference occurred in 84.6% with the back compared to 46.2% with the front of the iPhone 12 facing the CIED. In vivo, activation of the magnet-sensitive switch occurred in 30 CIED patients (18.3%; 21 pacemaker, 9 ICD) when the iPhone 12 was placed in close proximity over the CIED pocket and the back of the phone was facing the skin. Multiple binary logistic regression analysis identified implantation depth (95% confidence interval 0.02-0.24) as an independent predictor of magnet-sensitive switch activation.

CONCLUSION

Magnetic field interactions occur only in close proximity and with precise alignment of the iPhone 12 and CIEDs. It is important to advise CIED patients to not put the iPhone 12 directly on the skin above the CIED. Further recommendations are not necessary.

Electromagnetic Field Associated With Dermoscope Magnets May Affect the Safety of Cardiac Implanted Electronic Devices Patients

Dermoscopy is currently used as an auxiliary tool in general dermatology. Since some commercially available dermoscopes have built-in magnets, electromagnetic interference (EMI) may occur when examining cardiac implantable electronic devices (CIED) patients. The aim of the study was to create maps of electromagnetic fields defining a safe distance in terms of EMI. The study was performed in laboratory conditions using measuring equipment specially designed for this purpose. The following dermoscopes have been tested: Illuco IDS-1100, Visiomed Luminis, Visiomed Luminis 2, Heine NC2 with and without a contact plate, DermLite DL4, and DermLite Handyscope. Measurements were made for the following set of lift-off distances: 5, 10, 20, 30, 40, 50, and 150 mm. Each 2D scan consisted of 10-line scans shifted from each other by 10 mm. The strength of the magnetic field decreased with the distance from the faceplate. The distribution of the magnetic field differed depending on the position of the magnets. The highest magnetic field was recorded in the center of the Heine NC2 faceplate (up to 8 mT). In most cases, at a distance of 10 mm, the magnetic field strength was measured below 1 mT, with the exception of Heine NC2 and Heine NC2 with a contact plate. All tested dermoscopes generated a magnetic field of <1 mT at the distance of 20 mm. The use of dermoscopes with built-in magnets may affect the functioning of CIEDs, and the impact may vary depending on the type of dermoscope.

Cardiac device troubleshooting in the intensive care unit: an educational review

Numerous patients with a cardiac implantable electronic device are admitted to the cardiac intensive care unit (ICU). When taking care of these patients, it is essential to have basic knowledge of potential device problems and how they could be tackled. This review summarizes common issues with pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization devices and provides a framework for troubleshooting in the ICU. In addition, specific aspects of intensive care that might interfere with cardiac devices are discussed.

Neuromuscular electrical stimulation for a dysphagic stroke patient with cardiac pacemaker using magnet mode change: A case report

BACKGROUND

Electromagnetic interference (EMI), means disturbance to the operation of implanted electrical devices caused by external sources. If cardiac pacemaker is implanted into the body, the risk of EMI should be considered when performing neuromuscular electrical stimulation (NMES). So far, no case has been reported that clinical magnets are used to safely manage the EMI risk of patients with cardiac pacemaker in NMES.

CASE SUMMARY

A 72-year-old male with swallowing disorder due to pure motor lacunar syndrome was transferred to rehabilitation department six days after the symptom onset. EMI risk needed be considered when implementing NMES on pharyngeal muscles, since cardiac pacemaker was implanted on his left chest due to the sick sinus syndrome. In the first NMES, the function of the pacemaker was directly monitored using telemetric instruments. From the second day, by a simple method of placing a magnet on the pacemaker, we chose to move the pacemaker into a mode that the device was not influenced by external stimulus. This magnet method has been used repeatedly for a year for the safe NMES treatment. We could remove Levin tube four months after the initial symptom and dysphagia related symptoms had not been noted during two-year follow-up period.

CONCLUSION

This report is the first case of dysphagia rehabilitation that EMI risk was handled using mode change of pacemaker with magnet. This method is unfamiliar to doctors, but safe and easy approach. This paper could be guidance for clinicians who need to treat patients with EMI risk.

Magnetic Interference on Cardiac Implantable Electronic Devices From Apple iPhone MagSafe Technology

Background

Magnet wireless charging is being utilized increasingly in current generation smartphones. Apple's MagSafe is a proprietary wireless charging technology with an array of magnets that has the capacity to generate magnet fieldstrength >50 gauss (G). We hypothesize that there is clinically significant magnet interference caused by Apple's MagSafe technology on cardiac implantable electronic devices (CIED).

Methods and Results

This study has an in vivo and an ex vivo component. The in vivo component consists of consecutive patients who presented to the electrophysiology laboratory with previously implanted CIEDs. The iPhone 12 Pro Max was directly placed on the skin over the pocket of these patients and the effect was studied by device interrogation. For the ex vivo component of the study, CIEDs from major device companies were tested for magnetic interference caused by iPhone 12 Pro Max through unopened packages. We found that iPhone 12 Pro Max resulted in clinically identifiable magnet interference in 3/3 (100%) participants in vivo and in 8/11 (72.7%) devices ex vivo.

Conclusions

Apple's iPhone 12 Pro Max MagSafe technology can cause magnet interference on CIEDs and has the potential to inhibit lifesaving therapy.

Appropriate Delivery of Antitachyarrhythmia Therapy Despite Magnet Placement Over Implanted Cardioverter-Defibrillator: A Case Report

The fundamental perioperative concern for patients with implantable cardioverter-defibrillators (ICDs) is the potential for electromagnetic interference (EMI) from monopolar electrosurgery. The ICD may interpret electromagnetic signals as a tachyarrhythmia and deliver an inappropriate shock to the patient. Magnet placement is often used to avoid this problem since a magnet will often deactivate an ICD's tachyarrhythmia therapy. We report a case in which magnet placement over an ICD failed to suspend tachyarrhythmia therapy because of imprecise magnet positioning. This case demonstrates the possibility for error when relying on a magnet to suspend tachyarrhythmia therapies.

Shortness of breath and palpitations in an elderly man: Bad device behavior or malfunction?

70-year-old male with sinus node dysfunction (SND) and paroxysmal atrial fibrillation presents with shortness of breath and palpitations. Presenting EKG shows AF with rapid ventricular rates requiring direct current cardioversion (DCCV). Post-DCCV EKG shows sinus rhythm with competing ventricular pacing. Device interrogation demonstrates the patient's generator at the elective replacement indicator (ERI) and has been forced to VVI 65 bpm causing dyssynchronous ventricular pacing and inducing AF. This case highlights the importance of close device follow up with timely PPM generator change prior to ERI, especially in patients with Medtronic Adapta devices, to avoid unnecessary dyssynchronous ventricular pacing. In addition, device manufacturers should focus on maintaining AV synchrony in pacemakers when they reach ERI.

Incidence of magnet mode in patients with implantable cardioverter defibrillators

PURPOSE

To determine the current incidence of antitachycardia therapy suspension due to magnet reversion in patients with implantable cardioverter defibrillators (ICDs).

METHODS

From March 2012 to September 2018, all St. Jude Medical ICD interrogations performed at the Deutsches Herzzentrum München were screened for stored events of antitachycardia therapy suspension caused by static magnetic fields (flux densities ≥ 1 mT as defined in St. Jude Medical ICDs) affecting the giant magnetoresistance (GMR) sensor. Intentional ICD deactivation or inappropriate magnet application in the hospital was classified as non-environmental electromagnetic interference (EMI) whereas in the case of any other stored magnet reversion, the event was classified as presumably environmental EMI.

RESULTS

Data from 201 St. Jude Medical ICD patients (mean age 62 ± 24 years, 165 males/36 females) were included in the analysis. ICD interrogations occurred at a mean follow-up of 25.1 months ± 15.6 months and summed up to a total of 464 patient-years of follow-up. A total number of 43 magnet reversion events were detected in 21 patients. Thirty-two events in 13 patients were presumably related to environmental EMI sources. Suspension of antitachycardia therapy only occurred in a temporary fashion. None of the patients experienced any ventricular tachyarrhythmia during ICD inhibition. The incidence of antitachycardia therapy suspension due to magnet reversion related to presumably environmental EMI sources was 6.9% per patient and year.

CONCLUSION

Although none of the patients experienced any harmful event, antitachycardia therapy suspension due to magnet reversion is a common issue. Patients should be well-educated about potential EMI sources as well as trained in handling them.

Recommendations for Perioperative Management of Patients with Cardiac Implantable Electronic Devices

SUMMARY – Four thousand cardiac implantable electronic devices (CIED) are implanted yearly in Croatia with constant increase. General anesthesia and surgery carry some specific risk for the patients with implanted CIEDs. Since most of the surgical procedures are performed in institutions without reprogramming devices available, or in the periods when they are unavailable, these guidelines aim to standardize the protocol for perioperative management of these patients. With this protocol, most of the procedures can be performed easily and, more importantly, safely in the majority of surgical patients.

Comparison of perioperative strategies in ICD patients: The perioperative ICD management study (PIM study)

BACKGROUND

The prevalence of patients with implanted cardioverter defibrillators (ICDs) and the frequency of surgery on these patients are steadily on the rise. Guidelines recommend preoperative ICD reprogramming, although this is sometimes difficult in clinical practice. Placing a magnet on the ICD is a practical alternative and even no inactivation is possible in selected cases.

METHODS

In this prospective observational study, we compared different perioperative ICD management strategies depending on the location of the surgery and the type of electrocautery used. Patients undergoing surgery above the umbilicus with monopolar electrocautery had their ICD therapy inactivated by reprogramming. When surgery below the navel or surgery above the navel with bipolar electrocautery was completed, ICD inactivation was performed using a magnet. No inactivation was performed on patients undergoing lower extremity surgery with bipolar electrocautery. Only ICD patients who were not pacemaker dependent were enrolled. After surgery, the ICDs were assessed regarding documented arrhythmias and parameters.

RESULTS

Out of 101 patients included in this study, the ICD was preoperatively reprogrammed in 42 patients (41.6%), a magnet was used on 45 patients (44.5%), and ICDs were not deactivated at all in 14 patients (13.9%). No intraoperative electromagnetic interference was detected. Postoperative ICD analysis demonstrated no changes of preset parameters.

CONCLUSIONS

All three tested ICD management strategies were proved safe in this study. Keeping the location of surgery and the type of electrocautery in mind, an intraoperative magnet or even no ICD deactivation at all could be feasible alternatives in surgery on patients with ICDs.

A Contactless Sensor for Pacemaker Pulse Detection: Design Hints and Performance Assessment

Continuous monitoring of pacemaker activity can provide valuable information to improve patients' follow-up. Concise information is stored in some types of pacemakers, whereas ECG can provide more detailed information, but requires electrodes and cannot be used for continuous monitoring. This study highlights the possibility of a continuous monitoring of pacemaker pulses by sensing magnetic field variations due to the current pulses. This can be achieved by means of a sensor coil positioned near the patient's thorax without any need for physical contact. A simplified model of coil response to pacemaker pulses is presented in this paper, along with circuits suitable for pulse detection. In vitro tests were carried out using real pacemakers immersed in saline solution; experimental data were used to assess the accuracy of the model and to evaluate the sensor performance. It was found that the coil signal amplitude decreases with increasing distance from the pacemaker lead wire. The sensor was able to easily perform pacemaker spike detection up to a distance of 12 cm from the pacemaker leads. The stimulation rate can be measured in real time with high accuracy. Since any electromagnetic pulse triggers the same coil response, EMI may corrupt sensor measurements and thus should be discriminated.

Physicians' knowledge of implantable defibrillator treatment: are we good enough?

Aims

When admitted to hospitals, patients with an implantable cardioverter defibrillator (ICD) are treated in a variety of departments. Physicians need to have basic ICD knowledge in order to provide the best possible care from implantation to the end of life. The aim of this study was to assess the levels of knowledge concerning ICD treatment among physicians active in Cardiology, Internal Medicine, and Geriatrics.

Methods and results

This cross-sectional comparative study, after stratified sampling, distributed 432 surveys in 18 hospitals with a response rate of 99.5%. As many as 349 (83%) physicians had experience with ICD patients; 288 (68%) rated their ICD knowledge to be low. According to predefined criteria, 175 (41%) physicians' scores reflected sufficient knowledge. There was a significant difference in the level of knowledge between specialities. Sufficient knowledge was reached by 56 (30%) of the physicians in Internal Medicine and 20 (19%) of them in Geriatrics, whereas in Cardiology 99 (71%) reached sufficient knowledge.

Conclusion

There is lack of basic knowledge in ICD treatment and clinical management among physicians. The majority of the respondents had prior experience in treating ICD patients. Over two-thirds of the physicians rated their knowledge to be low, while test scores revealed sufficient knowledge in only 41% of the physicians surveyed. The lack of ICD knowledge is most prominent in Internal Medicine and Geriatrics, but it also extends to physicians in Cardiology departments. With an increasing number of ICD patients, it is of great importance to fill this knowledge gap as soon as possible.

Hybrid bodies and the materiality of everyday life: how people living with pacemakers and defibrillators reinvent everyday routines and intimate relations

Technologies inside bodies pose new challenges in a technological culture. For people with pacemakers and defibrillators, activities such as passing security controls at airports, using electromagnetic machines, electrical domestic appliances and electronic devices, and even intimate contacts with their loved ones can turn into events where the proper functioning of their device may be at risk. Anticipation of potentially harmful events and situations thus becomes an important part of the choreography of everyday life. Technologies inside bodies not only pose a challenge for patients living with these devices but also to theorising body-technology relations. Whereas researchers usually address the merging of bodies and technologies, implants ask us to do the opposite as well. How are we to understand human-technology relations in which technologies should not entangle with bodies because they serve other purposes? Based on a study of the daily life practices of people with pacemakers and defibrillators in the Netherlands and the US, I argue that disentanglement work, i.e. work involved to prevent entanglements with objects and people that may inflict harm upon implanted devices, is key to understanding how hybrid bodies can survive in today's densely populated technological landscape.

Management of cardiac implantable electronic devices during interventional pulmonology procedures

An increasing number of patients are receiving cardiac implantable electronic devices (CIED) now. Many of them need pulmonary procedures for various indications including, but not limited to, lung cancer and benign endobronchial lesions. Over the last two decades, interventional pulmonology (IP) has expanded its scope to include various modalities that use heat and electrical energy and in the process, create electromagnetic field in the vicinity. This raises concerns for electromagnetic interference (EMI) causing abnormal behavior in the CIEDs. While guidelines and recommendations on the peri-procedural management of CIEDs do exist, none of them directly address the pulmonary procedures. In this paper, we strive to review the available literature pertaining to the management of CIEDs in the context of EMI caused by the various IP procedures.

Cardiovascular implantable electronic devices: a review of the dangers and difficulties in MR scanning and attempts to improve safety

Abstract

An increasing number of patients are being treated with cardiovascular implantable electronic devices (CIEDs), many of which are MR conditional. There is a lack of literature on the safe scanning of MR conditional CIEDs. This review article discusses MR imaging safety in patients with implanted CIEDs. Guidelines on safe use and indications of imaging patients with MR conditional CIEDs are described, followed by a pictorial essay of the radiographic features of these devices. We also discuss the challenges of monitoring the patient in the MR environment, advances in MRI conditional imaging of devices, availability, limitations and workflow including vendor-specific and other collaborative efforts to simplify the scanning process. Radiologists must be able to facilitate the safe utilization of MR imaging in patients who have CIEDs. A thorough knowledge of the hazards of imaging non-MR compatible devices is required as well as knowing how to correctly identify and manage the imaging of patients with MR conditional CIEDs. Finally, we propose steps required to facilitate the safe scanning of patients with MR conditional CIEDs adopted in our institution and a contingency plan in the event that an inadvertent MR scan of a patient with a MRI unsafe CIED should occur.

Main Messages

• Risks of MR imaging in patients who have CIEDs have been worked around.

• There are many technical limitations in enabling safe MR scanning of CIEDs.

• Radiological identification of MRI-conditional status of CIEDs is useful.

• Standardizing conditions for safe MRI scanning is important.

• We offer example algorithms for facilitating safe MRI scanning of CIEDs.

Perioperative management of patients with cardiac implantable electronic devices

The use of implantable cardiac devices in people of all ages is increasing, especially in the elderly population: patients with pacemakers, cardioverter-defibrillators or cardiac resynchronization therapy devices regularly present for surgery for non-cardiac causes. This review was made in order to collect and analyze the latest evidence for the proper management of implantable cardiac devices in the perioperative period. Through a detailed exploration of PubMed, Academic Search Complete (EBSCO), ClinicalKey, Cochrane (Ovid), the search software UpToDate, textbooks and patents freely available to the public on Google, we selected 33 monographs, which matched the objectives of this publication.

A practical approach to perioperative management of cardiac implantable electronic devices

With the increased use of cardiac implantable electronic devices (CIEDs), it is increasingly important to recognise the unique challenges involved in the management of patients with CIEDs who are undergoing surgery. Practice advisories and consensus statements have been issued by the American Society of Anesthesiologists and the Heart Rhythm Society, advocating a multidisciplinary approach. This review discusses and presents a practical approach to perioperative CIED management in the Singapore context.

Low risk of electromagnetic interference between smartphones and contemporary implantable cardioverter defibrillators

AIMS

Manufacturers of implantable cardioverter defibrillators (ICDs) recommend that cell phones be maintained at a distance of ∼15 cm from the implanted device in order to avoid risk of dysfunction due to electromagnetic interference (EMI). Data relating to this issue are outdated and do not reflect modern technology. Our aim was to evaluate whether EMI is still an issue with contemporary ICDs and smartphones.

METHODS AND RESULTS

Consecutive patients implanted with a wireless-enabled ICD were tested for potential interference with two models of recent 4G smartphones in conditions intended to maximize risk of EMI. A magnet effect (due to the phone speakers) was tested by placing the smartphones in the standby mode directly over the ICD generator. The presence of EMI artefacts on the real-time electrograms was evaluated by placing the smartphones in the standby, dialling, and operating modes directly over the generator casing and over the parasternal region in the vicinity of the ventricular lead. A total of 63 patients equipped with 29 different models of single, dual, or biventricular ICDs from five major manufacturers were included. None of the patients showed any evidence of interference with the smartphones during any of the 882 tests.

CONCLUSION

The risk of EMI between modern smartphones and contemporary ICDs is low. This is probably due to the filters incorporated in the ICDs and low emission by the phones, as well as the small size of the magnets in the smartphones tested.

STUDY REGISTRATION

NCT02330900 (http://www.clinicaltrials.gov).

Radiotherapy in patients with pacemakers and implantable cardioverter defibrillators: a literature review

An increasing number of patients with implantable cardiac rhythm devices undergo radiotherapy (RT) for cancer and are thereby exposed to the risk of device failure. Current safety recommendations seem to have limitations by not accounting for the risk of pacemakers and implantable cardioverter defibrillators malfunctioning at low radiation doses. Besides scant knowledge about optimal safety measures, only little is known about the exact prevalence of patients with devices undergoing RT. In this review, we provide a short overview of the principles of RT and present the current evidence on the predictors and mechanisms of device malfunctions during RT. We also summarize practical recommendations from recent publications and from the industry. Strongly associated with beam energy of photon RT, device malfunctions occur at ∼3% of RT courses, posing a substantial issue in clinical practice. Malfunctions described in the literature typically consist of transient software disturbances and only seldom manifest as a permanent damage of the device. Through close cooperation between cardiologists and oncologists, a tailored individualized approach might be necessary in this patient group in waiting time for updated international guidelines in the field.

Biventricular Pacemakers in Patients With Heart Failure

Patients with heart failure may benefit from implantation of a biventricular pacemaker. This article discusses the indications for biventricular pacemaker implantation and the assessment of patients with biventricular pacemakers. Biventricular pacemakers require more assessments than do traditional single- or dual-chamber pacemakers.

Correlation of geomagnetic activity with implantable cardioverter defibrillator shocks and antitachycardia pacing

OBJECTIVE

To investigate a potential relationship between implantable cardioverter defibrillator (ICD) therapies and daily geomagnetic activity (GMA) recorded in a large database.

PATIENTS AND METHODS

The ALTITUDE database, derived from the Boston Scientific LATITUDE remote monitoring system, was retrospectively analyzed for the frequency of ICD therapies. Daily GMA was expressed as the planetary K-index and the integrated A-index and was graded as levels I (quiet), II (unsettled), III (active), and IV (storm).

RESULTS

A daily mean ± SD of 59,468±11,397 patients were monitored between January 1, 2009, and May 15, 2012. The distribution of days according to GMA was as follows: level I, 924/1231 (75%); level II, 226/1231 (18%); level III, 60/1231 (5%); and level IV, 21/1231 (2%). The daily mean ± SD numbers of ICD shocks received per 1000 active patients in the database were 1.29±0.47, 1.17±0.46, 1.03±0.37, and 0.94±0.29 on level I, II, III, and IV days, respectively; the daily mean ± SD sums of shocks and antitachycardia pacing therapies were 9.29±2.86, 8.46±2.45, 7.92±1.80, and 7.83±2.28 on quiet, unsettled, active, and storm days, respectively. A significant inverse relationship between GMA and frequency of ICD therapies was identified, with the most pronounced difference between level I and level IV days (P<.001 for shocks; P=.008 for shocks + antitachycardia pacing).

CONCLUSION

In a large-scale cohort analysis, ICD therapies were delivered less frequently on days of higher GMA, confirming the previous pilot data and suggesting that higher GMA does not pose an increased risk of arrhythmias using ICD therapies as a surrogate marker. Further studies are needed to gain an in-depth understanding of the underlying mechanisms.

Defibrillator patients should not be denied a peaceful death

BACKGROUND

Implantable defibrillators (ICDs) prevent sudden cardiac death. With declining health, ICD therapy may prolong death and expose the patient to unnecessary pain and anxiety. Few studies have addressed end of life care in ICD patients. The objective of this study was to investigate end of life in ICD patients, with respect to location of death; duration between do-not-resuscitate (DNR)-orders and deactivation of ICD therapy or DNR and time of death.

METHODS AND RESULTS

A descriptive analysis of 65 deceased ICD patients, all whom had a written DNR-order before death, is presented. The majority (86%) was treated in hospitals, mainly (63%) university hospitals, and many (33%) in cardiology wards. Despite DNR-order, ICD shock therapy was active in 51% of all patients. In those with therapy deactivated at death, therapy deactivation was carried out two days or more after DNR-order in more than a third (38%). The time from DNR decision to death in patients with therapy active had a median of four days (IQR 1-38). During the last 24h of life, 24% of the patients experienced shock treatment.

CONCLUSIONS

The majority of ICD patients with a DNR-order were treated in university hospitals. More than half still had shock treatment active at time of death with a median of four days or more between DNR decision and death. Patients with therapy deactivated, two days or more elapsed in more than a third from DNR decision to deactivation of therapy, exposing patients to a high risk of painful shocks before death.

The role of the anesthesiologist in the care of the parturient with cardiac disease

Women with cardiac disease constitute a growing percentage of parturients, and in many series cardiac disease is the leading cause of maternal mortality. Involvement of anesthesiologists in the planning for and management of delivery in these women can improve the experience and potentially the outcome of these patients. Communication with the anesthesiology team about particularly complex cases is essential to avoid both medical complications and inter-disciplinary disagreements. The specific role and contributions of the anesthesiology team will depend significantly on the nature of the institution and the organization of the (obstetric) anesthesiology service.