iPad2(R) use in patients with implantable cardioverter defibrillators causes electromagnetic interference: the EMIT Study

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.

[Electromagnetic interference : Pacemakers, cardiac resynchronization therapy devices, implantable cardioverter-defibrillator]

Patients with cardiac pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy devices (CRT) are exposed to different types of electromagnetic interference (EMI) at home and at work. Due to the constantly increasing role of electrically active appliances in daily use and the introduction of new therapy concepts such as the leadless cardiac pacemaker and the subcutaneous defibrillator, this topic is of great relevance. The further development of the implanted devices and the almost complete use of bipolar leads has reduced the overall risk of EMI. This review article provides information about the current status of possible interference in the private environment and how to avoid it. In addition, information is provided on how to deal with occupational sources of interference.

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.

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.

Interference of cardiovascular implantable electronic devices by static electric and magnetic fields

Introduction: Electromagnetic interference (EMI) of cardiovascular implantable electronic devices (CIED) can lead to malfunctions and pose a danger for implant carriers. The increased use of DC technologies, e.g. in electric mobility, creates more static fields representing an increasing hazard for implant carriers.Areas covered: A combination of approaches was used to determine thresholds for EMI by static fields. A literature search was conducted to identify relevant EMI mechanisms and to extract possible thresholds. The literature search revealed four interference mechanisms caused by static magnetic fields and none for static electric fields. Due to the scarce information on motion-induced EMI, numerical simulations were performed to obtain a threshold. The simulation results were evaluated using medical product standards and benchmark tests on commercially available CIEDs. The results show that motion-induced interference should not occur below the activation of the magnetic safety switch (reed switch or Hall-effect sensor, MSS).Expert opinion: The determined threshold for motion-induced EMI at 24.8 mT shows that the MSS activation is still the most relevant mechanism that can occur at 0.8 mT. Limit values for the general population do not protect implant carriers from EMI.

Comprehensive multicomponent cardiac rehabilitation in cardiac implantable electronic devices recipients: a consensus document from the European Association of Preventive Cardiology (EAPC; Secondary prevention and rehabilitation section) and European Heart Rhythm Association (EHRA)

Cardiac rehabilitation (CR) is a multidisciplinary intervention including patient assessment and medical actions to promote stabilization, management of cardiovascular risk factors, vocational support, psychosocial management, physical activity counselling, and prescription of exercise training. Millions of people with cardiac implantable electronic devices live in Europe and their numbers are progressively increasing, therefore, large subsets of patients admitted in CR facilities have a cardiac implantable electronic device. Patients who are cardiac implantable electronic devices recipients are considered eligible for a CR programme. This is not only related to the underlying heart disease but also to specific issues, such as psychological adaptation to living with an implanted device and, in implantable cardioverter-defibrillator patients, the risk of arrhythmia, syncope, and sudden cardiac death. Therefore, these patients should receive special attention, as their needs may differ from other patients participating in CR. As evidence from studies of CR in patients with cardiac implantable electronic devices is sparse, detailed clinical practice guidelines are lacking. Here, we aim to provide practical recommendations for CR in cardiac implantable electronic devices recipients in order to increase CR implementation, efficacy, and safety in this subset of patients.

Comprehensive multicomponent cardiac rehabilitation in cardiac implantable electronic devices recipients: a consensus document from the European Association of Preventive Cardiology (EAPC; Secondary prevention and rehabilitation section) and European Heart Rhythm Association (EHRA)

Cardiac rehabilitation (CR) is a multidisciplinary intervention including patient assessment and medical actions to promote stabilization, management of cardiovascular risk factors, vocational support, psychosocial management, physical activity counselling, and prescription of exercise training. Millions of people with cardiac implantable electronic devices live in Europe and their numbers are progressively increasing, therefore, large subsets of patients admitted in CR facilities have a cardiac implantable electronic device. Patients who are cardiac implantable electronic devices recipients are considered eligible for a CR programme. This is not only related to the underlying heart disease but also to specific issues, such as psychological adaptation to living with an implanted device and, in implantable cardioverter-defibrillator patients, the risk of arrhythmia, syncope, and sudden cardiac death. Therefore, these patients should receive special attention, as their needs may differ from other patients participating in CR. As evidence from studies of CR in patients with cardiac implantable electronic devices is sparse, detailed clinical practice guidelines are lacking. Here, we aim to provide practical recommendations for CR in cardiac implantable electronic devices recipients in order to increase CR implementation, efficacy, and safety in this subset of 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.

Assessment of the Safety Risk of Dermatoscope Magnets in Patients With Cardiovascular Implanted Electronic Devices

Importance

Cardiovascular implanted electronic devices (CIEDs) are susceptible to electromagnetic interference. Dermatologists regularly use devices containing magnets, including dermatoscopes and their attachments, which could pose a hazard to patients with CIEDs.

Objective

To investigate the safety risk of magnets in dermatoscopes to patients with CIEDs.

Design, Setting, and Participants

This cross-sectional observational study was conducted between January 1, 2018, and March 31, 2018, in a controlled laboratory setting. Two experiments were performed. In the first experiment (performed in the Dermatology Service at Memorial Sloan Kettering Cancer Center, New York), dermatoscopes that contain magnets were obtained from 3 manufacturers. Using a magnometer, the magnetic field strength of the dermatoscopes was measured over the magnet; at the faceplate; and at a distance of 0.5 cm, 1 cm and 15 cm away from the faceplate. In the second experiment (performed in the University Heart Center Zurich, Zurich, Switzerland), ex vivo measurements were conducted to determine how the dermatoscopes affected old-generation and new generation CIEDs (pacemakers and implantable defibrillators).

Main Outcomes and Measures

Magnetic field strength as measured directly over the dermatoscope magnet; at the faceplate; and at distances of 0.5 cm, 1 cm, and 15 cm from the faceplate. Pacemaker and defibrillator operation when exposed to dermatoscopes.

Results

After conducting 24 measurements, the magnetic field (measured in gauss [G]) strength varied between 24.26 G and 163.04 G over the dermatoscope magnet, between 2.22 G and 9.98 G at the dermatoscope faceplate, between 0.82 G and 2.4 G at a distance of 0.5 cm, and between 0.5 G and 1.04 G at a distance of 1 cm; it was 0 for all devices at a 15 cm distance. The field strength at the faceplate was found to be generally below the CIED industry standard safety threshold. None of the dermatoscopes in the ex vivo experiment exerted any demonstrable disruptions or changes to the CIEDs.

Conclusions and Relevance

In real life, dermatoscope magnets likely present no measurable safety risk to patients with CIEDs. Using the polarized noncontact mode permits dermoscopy to be performed at least 0.5 cm from the skin surface, where the magnetic field strength was well below the 5-G safety threshold.

Management of Patients With Cardiovascular Implantable Electronic Devices in Dental, Oral, and Maxillofacial Surgery

The prevalence of cardiovascular implantable electronic devices as life-prolonging and life-saving devices has evolved from a treatment of last resort to a first-line therapy for an increasing number of patients. As these devices become more and more popular in the general population, dental providers utilizing instruments and medications should be aware of dental equipment and medications that may affect these devices and understand the management of patients with these devices. This review article will discuss the various types and indications for pacemakers and implantable cardioverter-defibrillators, common drugs and instruments affecting these devices, and management of patients with these devices implanted for cardiac dysrhythmias.