Electromagnetic interference and implanted cardiac devices: the medical environment (part II)

New-generation electronic appliances and cardiac implantable electronic devices: a systematic literature review of mechanisms and in vivo studies

INTRODUCTION

Cardiac implantable electronic device (CIED) functions are susceptible to electromagnetic interference (EMI) from electromagnetic fields (EMF). Data on EMI risks from new-generation electronic appliances (EA) are limited.

OBJECTIVE

We performed a systematic literature review on the mechanisms of EMI, current evidence, and recently published trials evaluating the effect of EMF on CIEDs from electric vehicles (EV), smartphone, and smartwatch technology and summarize its safety data.

METHODS

Electronic databases, including PubMed and EMBASE, were searched for in vivo studies evaluating EMF strength and incidence between CIEDs and commercial EVs, new-generation smartphones, and new-generation smartwatches.

RESULTS

A total of ten studies (three on EVs, five on smartphones, one on smartphones, one on smartphones and smartwatches) were included in our systematic review. There was no report of EMI incidence associated with EVs or smartwatches. Magnet-containing smartphones (iPhone 12) can cause EMI when placed directly over CIEDs - thereby triggering the magnet mode; otherwise, no report of EMI was observed with other positions or smartphone models.

CONCLUSION

Current evidence suggests CIED recipients are safe from general interaction with EVs/HEVs, smartphones, and smartwatches. Strictly, results may only be applied to commercial brands or models tested in the published studies. There is limited data on EMI risk from EVs wireless charging and smartphones with MagSafe technology.

The Impact of Electromagnetic Interference from Charging All-electric Vehicles on Implantable Cardioverter-defibrillator Performance

Electric vehicles (EVs) are growing in popularity and in general use. The effect of electromagnetic interference (EMI) caused by supercharging all-electric vehicles on implantable cardioverter-defibrillator (ICD) function has not been studied. The objective of this study was to determine the extent of the effect of EMI from charging Tesla all-electric vehicles (Tesla, Inc., Austin, TX, USA) on cardiac implantable electronic device function. A proof-of-concept study was performed to explore the potential effect of EMI from Tesla vehicles while charging the battery using a 220-V wall charger and a 480-V Supercharger. Tesla Model S and Model X vehicles were used for this study. We enrolled 34 patients with stable ICD function for the initial phase using the standard wall charger, followed by an additional 35 patients for the second phase using the Supercharger. Tracings were obtained at nominal and highest sensitivity settings while patients sat in the driver's seat, passenger seat, back seats, and facing the charging port. In each position, the device and the patient were monitored in real time by a certified technician for any inappropriate sensing and/or delivery of therapies. A medical magnet was also available on site. Emergency medical services and physician supervision were available at all times, and patients were contacted the following day to ensure their well-being. No device interactions were identified at both the nominal and highest sensitivity settings of each ICD during exposure to vehicle charging using a Tesla 220-V wall charger and a 480-V Supercharger at any of the five positions in and around each vehicle. Interaction was defined as oversensing, undersensing, mode switch, or upper rate tracking behavior. There was also no damage to any ICD, and no inappropriate shocks were administered to any patient. In conclusion, transvenous ICD function is not interrupted by EMI transmitted while charging Tesla vehicles using either the 220-V wall charger or the 480-V Supercharger.

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Cardiac wireless implantable medical devices (CWIMD) have brought a paradigm shift in monitoring and treating various cardiac conditions, including heart failure, arrhythmias, and hypertension. One of the key elements in CWIMD is the implant antenna which uses radio frequency (RF) technology to wirelessly communicate and transmit data to external devices. However, wireless communication with a deeply implanted antenna using RF can be challenging due to the significant loss of electromagnetic (EM) signal at the air-skin interface, and second, due to the propagation and reflection of EM waves from different tissue boundaries. The air-skin interface loss of the EM wave is pronounced due to the absence of a matching medium. This paper investigates the EM propagation losses in the human body and presents a choice of optimal frequency for the design of the cardiac implant antenna and the dielectric properties of the matching medium. First, the dielectric properties of all tissues present in the human thorax including skin, fat, muscle, cartilage, and heart are analyzed as a function of frequency to study the EM wave absorption at different frequencies. Second, the penetration of EM waves inside the biological tissues is analyzed as a function of frequency. Third, a transmission line (TL) formalism approach is adopted to examine the optimal frequency band for designing a cardiac implant antenna and the matching medium for the air-skin interface. Finally, experimental validation is performed at two ISM frequencies, 433 MHz and 915 MHz, selected from the optimal frequency band (0.4-1.5 GHz) suggested by our analytical investigation. For experimental validation, two off-the-shelf flexible dipole antennas operating at selected ISM frequencies were used. The numerical and experimental findings suggested that for the specific application of a cardiac implant with a penetration depth of 7-17 cm, the most effective frequency range for operation is within 0.4-1.5 GHz. The findings based on the dielectric properties of thorax tissues, the penetration depth of EM waves, and the optimal frequency band have provided valuable information on developing and optimizing CWIMDs for cardiac care applications.

Electroconvulsive Therapy in Patients With Cardiac Implantable Electronic Devices: A Case Report and Systematic Review of Published Cases

OBJECTIVE

The aims of the study were to report the case of a 54-year-old man with recurrent depressive disorder with multiple medical comorbidities having a dual-chamber pacemaker, treated successfully with 11 sessions of electroconvulsive therapy, and to conduct a systematic review of published cases documenting the use of electroconvulsive therapy (ECT) in patients with cardiac implantable electronic devices (CIEDs) for treating major psychiatric disorders.

METHODS

We searched electronic databases (MEDLINE, PubMed, Google Scholar, Embase, Cochrane Library, PsycINFO, and Crossref) and included studies reporting on the use of electroconvulsive therapy in patients with CIEDs.

RESULTS

Thirty-five publications across 53 years (1967-2021) reported on 76 patients (including current report) who received a pooled total of 979 modified ECT sessions. The most common adverse events were premature ventricular contraction and hypertension. There have been no reports of serious adverse effects that necessitated the cessation of ECT.

CONCLUSIONS

Electroconvulsive therapy is a safe and efficacious treatment for major psychiatric disorders, and the presence of CIEDs should not delay or deter the use of ECT in these patients.

Sudden Occurrence of Pacemaker Capture Failure during Irreversible Electroporation Ablation for Prostate Cancer in Post-COVID-19 Patient: A Case Report

Irreversible electroporation (IRE) ablation is a novel treatment option for localized prostate cancer. Here, we present a case of an abrupt and fatal arrhythmia during the IRE procedure in a prostate cancer patient with an implanted permanent pacemaker. A 78-year-old male patient with a pacemaker due to sick sinus syndrome and syncope was scheduled for IRE prostate ablation surgery under general anesthesia. He had a history of recovering from coronavirus disease 2019 (COVID-19) after having been vaccinated against it and recovered without sequalae. Pacemaker interrogation and reprogramming to asynchronous AOO mode was carried out before surgery, however, sinus pause occurred repeatedly during ablation pulse delivery. After the first sinus pause of 2.25 s there was a decrease in continuous arterial blood pressure (ABP). During the delivery of the second and third pulses, identical sinus pauses were observed due to failure to capture. However, the atrial-paced rhythm recovered instantly, and vital signs became acceptable. Although sinus pause recovered gradually, the duration thereof was increased by the delivery of more IRE pulses, with a subsequent abrupt decrease seen in blood pressure. The pacemaker was urgently reprogrammed to DOO mode, after which there were no further pacing failures and no hemodynamic adverse events. For patients with pacemakers, close cardiac monitoring in addition to the interrogation of the pacemaker during the electromagnetic interference (EMI) procedure is recommended, especially in the case of having a disease that may aggravate cardiac vulnerability, such as COVID-19.

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.

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.

Deep brain stimulation and electromagnetic interference

Deep brain stimulation (DBS) has evolved into an approved and efficacious treatment for movement, obsessive-compulsive, and epilepsy disorders that are refractory to medical therapy, with current investigation into other disease conditions. However, there are unintentional and intentional sources of external electromagnetic interference (EMI) that can lead to either malfunctioning or damaged DBS devices, as well as injury to human tissue. Comprehensive studies and guidelines on such topics in the medical literature are scarce. Herein, we review the principles behind EMI, as well as the various potential sources of interference, both unintentional (e.g. stray EMI fields) and intentional (e.g. MRI scans, "brainjacking"). Additionally, we employ the Manufacturer and User Device Facility Experience (MAUDE) database to assess real-world instances of EMI (e.g., airport body scanners, magnetic resonance imaging (MRI), and electrosurgery) affecting DBS devices commonly implanted in the United States (US).

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.

An in vitro Evaluation of the Effect of Transient Electromagnetic Fields on Pacemakers and Clinical Mitigation Measures

Background: The effect of transient electromagnetic fields on the function of pacemakers is not well-evaluated. There is a lack of effective methods for clinicians to reduce electromagnetic susceptibility (EMS) during implantation of pacemakers. This study aimed to evaluate whether a novel method of handling the excess leads in the pocket can lower the EMS of pacemakers and consequently reduce the effect of electromagnetic interference caused by transient electromagnetic fields on pacemakers.

Methods: An in vitro chest model was established to simulate the clinical condition of dual-chamber pacemaker implantation. Three different intertwining patterns of excess leads were examined: parallel, twisted once, and multiple twisted-pair. Oscillated currents were injected into a copper electrical wire set horizontally above the model to create a radiated magnetic field to simulate the transient daily electromagnetic exposure of pacemakers. The electromagnetic induction of current was measured. The occurrence of EMS-related adverse events was evaluated when the induced pulsed voltage was applied.

Results: Transient electromagnetic fields can induce electromagnetic noise in the pacing loop and inhibit the release of pacing pulses. The multiple twisted-pair intertwining pattern of excess leads was associated with a lower induced voltage amplitude than both the parallel and once-twisted patterns (P < 0.001). Even once twisted could significantly reduce induced voltage amplitude compared to not twisted (P < 0.001). A lower incidence of pacing inhibition was also observed in the multiple twisted-pair group than in the other two groups (P < 0.001).

Conclusions: Transient electromagnetic fields can cause pacing inhibition. Twisting the excess leads for multiple turns in the pocket is an effective method to reduce the EMS of the dual-chamber pacemaker.

Safety of electronic massagers in patients with cardiac implantable electronic devices

BACKGROUND

Current recommendations by cardiac implantable electronic devices (CIEDs) manufacturers on electromagnetic interference (EMI) are based on extrapolations of studies exposing CIEDs to electromagnetic fields produced by Helmholtz coils and industrial equipment. There are currently little data whether commercially available electronic massagers can cause EMI in CIEDs in vivo. This is of interest as the use of electronic massagers is common in Asia.

METHODS

The study evaluated CIED patients before, during and after a 10-minute exposure to a commercially available electronic backrest upper body massager. Post-exposure sensing, pacing threshold, and lead impedance were compared to baseline values. The presence of artefacts, EMI, and adverse clinical events during exposure was recorded.

RESULTS

Eighty-six patients (59 pacemakers and 27 implantable cardioverter-defibrillators) with a total of 151 leads (60 atrial, 86 right ventricular, and 5 left ventricular) were evaluated. There was no incidence of EMI causing inappropriate inhibition of pacing or inappropriate defibrillation. There was no significant difference in the pacing threshold, sensing, and lead impedance post-exposure compared to baseline values.

CONCLUSION

Our study, though limited by small numbers and exposure to only 1 type of electronic massager, shows that it is potentially safe for patients with CIEDs to use commercially available electronic massagers with similar characteristics as the one tested in this study.

Electromagnetic interference in cardiac electronic implants caused by novel electrical appliances emitting electromagnetic fields in the intermediate frequency range: a systematic review

Electromagnetic fields (EMF) in the intermediate frequency (IF) range are generated by many novel electrical appliances, including electric vehicles, radiofrequency identification systems, induction hobs, or energy supply systems, such as wireless charging systems. The aim of this systematic review is to evaluate whether cardiovascular implantable electronic devices (CIEDs) are susceptible to electromagnetic interference (EMI) in the IF range (1 kHz-1 MHz). Additionally, we discuss the advantages and disadvantages of the different types of studies used to investigate EMI. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, we collected and evaluated studies examining EMI in in vivo studies, in vitro studies (phantom studies, benchmark tests), and simulation studies. Our analysis revealed that cardiac implants are susceptible to malfunction induced by EMF in the IF range. Electromagnetic interference may in particular be provoked by security systems and induction hobs. The results of the studies evaluated in this systematic review further indicate that the likelihood for EMI is dependent on exposure-related parameters (field strength, frequency, and modulation) and on implant- as well as on lead-related parameters (model, type of implant, implant sensitivity setting, lead configuration, and implantation site). The review shows that the factors influencing EMI are not sufficiently characterized and EMF limit values for CIED patients cannot be derived yet. Future studies should therefore, consider exposure-related parameters as well as implant- and lead-related parameters systematically. Additionally, worst-case scenarios should be considered in all study types where possible.

Electromagnetic interference on cardiac pacemakers and implantable cardioverter defibrillators during endoscopy as reported to the US Federal Drug Administration

INTRODUCTION

More than 3 million patients have a cardiac implanted electronic device (CIED) such as a pacemaker or implanted cardioverter-defibrillator in the USA. These devices are susceptible to electromagnetic interference (EMI) leading to malfunction and injury. Radiofrequency energy, the most common modality for obtaining hemostasis during endoscopy, is the most common source of EMI. Few studies have evaluated the effect of endoscopic radiofrequency energy on CIEDs. We aim to characterize CIED dysfunction related to endoscopic procedures. We hypothesize that EMI from endoscopic energy can result in patient injury.

METHODS

We queried the Manufacturer and User Facility Device Experience (MAUDE) database for CIED dysfunction related to electrosurgical devices over a 10-year period (2009-2019). CIED dysfunction events were identified using seven problem codes (malfunction, electromagnetic interference, ambient noise, pacing problem, over-sensing, inappropriate shock, defibrillation). These were cross-referenced for the terms "cautery, electrocautery, endoscopy, esophagus, colonoscopy, colon, esophagoscopy, and esophagogastroduodenoscopy." Reports were individually reviewed to confirm and characterize CIED malfunction due to an endoscopic procedure.

RESULTS

A search for CIED dysfunction resulted in 43,759 reports. Three hundred and eleven reports (0.7%) were associated with electrocautery, and of these, 45 reports (14.5%) included endoscopy. Ten reports involving endoscopy (22%) specified upper (3, 7%) or lower (7, 16%) endoscopy while the remainder were non-specific. Twenty-six of reports involving endoscopy (58%) suffered injury because of CIED dysfunction: Of these, 17 (65%) received inappropriate shocks, 5 (19%) had pacing inhibition with bradycardia or asystole, 3 (12%) had CIED damage requiring explant and replacement, and 1 (4%) patient suffered ventricular tachycardia requiring hospital admission.

CONCLUSION

The use of energy during endoscopy can cause dysfunction of CIEDs. This most commonly results in inappropriate defibrillation, symptomatic bradycardia, and asystole. Patients with CIEDs undergoing endoscopy should undergo pre- and post-procedure device interrogation and re-programming to avoid patient injury.

Safety of bioelectrical impedance analysis in advanced heart failure patients

BACKGROUND

Cardiac cachexia and frailty are major complications of advanced heart failure (AHF). Bioelectrical impedance analysis (BIA) may provide valuable information regarding fluid balance, muscle mass and prognosis. The main concerns regarding the use of BIA in AHF patients remain arrhythmias and electromagnetic interferences with cardiac implantable electronic devices (CIEDs). Reliable data regarding patients on continuous-flow ventricular assist device (cf-VAD) remain scarce. The aim of this study is to evaluate the safety of BIA in AHF patients on pro-arrhythmogenic therapy with an implanted CIED and/or with a cf-VAD.

METHODS

We prospectively performed 217 BIA measurements in 143 AHF patients at risk of severe arrhythmias due to inotropic support/a history of ventricular arrhythmias and/or treated with CIED, including 104 patients with an ICD, CRT or pacemaker and 95 patients with a cf-VAD. All patients were under continuous Electrocardiogram (ECG) monitoring and clinical surveillance for 24 hours.

RESULTS

No adverse events were observed during the 217 BIA measurements: No rhythm disturbances were documented in the telemetric monitoring during or within 30 minutes after the measurement. CIEDs showed no malfunction, regardless of the location measured or the device manufacturer. In particular, no inappropriate shocks were observed. No alarms, flow disturbances, or malfunctions of the cf-VAD occurred during or after the measurements.

CONCLUSION

We consider BIA a safe measurement with major clinical relevance in our cohort of AHF patients, despite an increased arrhythmic potential on inotropic support or the presence of implanted electronic devices (ICD, CRT, pacemaker and cf-VAD).

Anesthetic consideration for patients with micra leadless pacemaker

MICRA, miniaturized leadless single chamber pacemaker, is inserted directly into the right ventricular myocardium via transcatheter approach. We present a case of a 66-year-old patient with a Micra pacemaker scheduled for kidney-pancreas transplant. The patient is pacemaker dependent. The preoperative cardiology consult did not comment on the need of reprogramming. One hour prior to the surgery, the anesthesia team was unable to locate the pacemaker on the chest wall. The Medtronic hotline was called, and the caregivers learned that the particular pacemaker is buried within the ventricular wall and is not responsive to an external magnet. Thus, the case was delayed and a cardiac electrophysiology team was contacted to reprogram the pacemaker to VOO (fixed ventricular pacing) mode. We suggest that the pacemaker can pose perioperative challenges due to its novelty, paucity of report, and guidelines.

Influence and safety of electronic apex locators in patients with cardiovascular implantable electronic devices: a systematic review

The widespread use of cardiovascular implantable electronic devices has increased concerns regarding using electronic apex locators in patients with these devices. This systematic review investigated the effects and safety of using electronic apex locators in patients with cardiovascular implantable electronic devices.

METHODS

An electronic search in the Cochrane Library, PubMed (MEDLINE), ScienceDirect, and Scientific Electronic Library Online (Scielo) databases for relevant articles published between December 2000 and December 2018 was performed. The search strategy centered on terms related to electronic apex locators use during root canal treatment in patients with cardiovascular implantable electronic devices.

RESULTS

Seven studies (five in vitro and two in vivo) fulfilled the inclusion criteria for this review. It was found that electronic apex locators can be used safely in patients with cardiovascular implantable electronic devices, when general precautions are followed.

CONCLUSIONS

Although the present review suggests that electronic apex locators can be used safely in patients with implantable cardioverter defibrillators, consultation with patients' cardiologists remains advisable.

[Cardiac implantable electronic devices : Electromagnetic interference from electrocauterization, lithotripsy and physiotherapy]

The management of patients with a cardiac implantable electronic device (CIED) poses a particular challenge in the peri-interventional and perioperative medical environment due to the many forms of possible electromagnetic interference. Although the devices encountered nowadays are of increasing complexity, the vast majority of procedures can be safely performed in patients. The existing position statements and recommendations, however, have a low level of evidence and are often contradictory. In the context of intraoperative electrocauterization, one of the most important sources of electromagnetic interference in the medical environment, recent studies have suggested an increasingly pragmatically perioperative CIED management, which is not represented in the existing recommendations. This article gives an example of these newer findings and reports the currently used and appropriately adapted perioperative CIED management protocol. Extracorporeal shock wave lithotripsy was thought to cause severe interference in CIED patients based on older studies and in vitro experiments. Although electromagnetic interference is possible, clinical observations with modern devices show that the procedure can generally be safely applied in CIED patients. Physiotherapy often utilizes a variety of electromechanical devices, which can be a relevant source of electromagnetic interference. Although some of these therapies can be safely used, coordination with the responsible CIED unit is recommended.

How Do Patients Understand Safety for Cardiac Implantable Devices? Importance of Postintervention Education

Aim

This study was designed to assess the effect of patient education on the knowledge of safety and awareness about living with cardiac implantable electronic devices (CIEDs) within the context of phase I cardiac rehabilitation.

Methods

The study was conducted with 28 newly implanted CIED patients who were included in “education group (EG)”. Patients were questioned with a survey about living with CIEDs and electromagnetic interference (EMI) before and 1 month after an extensive constructed interview. Ninety-three patients who had been living with CIEDs were included in the “without education group (woEG)”.

Results

Patients in EG had improved awareness on topics related to physical and daily life activities including work, driving, sports and sexual activities, EMI of household items, harmful equipment, and some of the medical devices in the hospital setting (p<0.05). Patients in EG gave significantly different percent of correct answers for doing exercise or sports, using the arm on the side of CIEDs, EMI of some of the household appliances, medical devices, and all of the harmful equipment compared to woEG (p<0.05).

Conclusion

It was demonstrated that a constructed education interview on safety of CIEDs and living with these devices within the context of phase I cardiac rehabilitation is important for improving the awareness of patients significantly. Thus, patients might achieve a faster adaptation to daily life and decrease disinformation and misperceptions and thus promote the quality of life after the device implantation.

In-vivo compatibility between pacemakers and dental equipment

In-vitro studies suggest that electromagnetic interference can occur under specific conditions involving proximity between electronic dental equipment and pacemakers. At present, in-vivo investigations to verify the effect of using electronic dental equipment in clinical conditions on patients with pacemakers are scarce. This study aimed to evaluate, in vivo, the effect of three commonly used electronic dental instruments - ultrasonic dental scaler, electric pulp tester, and electronic apex locator - on patients with different pacemaker brands and configurations. Sixty-six consecutive non-pacemaker-dependent patients were enrolled during regular electrophysiology follow-up visits. Electronic dental tools were operated while the pacemaker was interrogated, and the intracardiac electrogram and electrocardiogram were recorded. No interferences were detected in the intracardiac electrogram of any patient during the tests with dental equipment. No abnormalities in pacemaker pacing and sensing function were observed, and no differences were found with respect to the variables, pacemaker brands, pacemaker configuration, or mode of application of the dental equipment. Electromagnetic interferences affecting the surface electrocardiogram, but not the intracardiac electrogram, were found in 25 (37.9%) patients, especially while using the ultrasonic dental scaler; the intrinsic function of the pacemakers was not affected. Under real clinical conditions, none of the electronic dental instruments tested interfered with pacemaker function.

FUSE certification enhances performance on a virtual computer based simulator for dispersive electrode placement

BACKGROUND

The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) has developed the fundamental use of surgical energy (FUSE) didactic curriculum in order to further understanding of the safe use of surgical energy. The virtual electrosurgical skill trainer (VEST) is being developed as a complementary simulation-based curriculum, with several modules already existing. Subsequently, a new VEST module has been developed about dispersive electrode placement. The purpose of this study is to assess knowledge about dispersive electrode placement in surgeons and surgical trainees in addition to describing a new VEST module.

METHODS

Forty-six subjects (n = 46) were recruited for participation at the 2016 SAGES conference Learning Center. Subjects were asked to complete demographic surveys, a five-question pre-test, and a five-question post-test after completing the VEST dispersive electrode module. Subjects were then asked to rate different aspects of the module using a five-point Likert scale questionnaire.

RESULTS

Mean pre-simulator and post-simulator assessment scores were 1.5 and 3.4, respectively, with Wilcoxon signed rank analysis showing a significant difference in the means (p < 0.05). Subjects were grouped by the presence (n = 12) or absence (n = 31) of prior FUSE experience and by training level. Mann-Whitney U testing showed no significant difference in pre-simulator assessment scores between attending surgeons and trainees (p > 0.05). In those with and without FUSE exposure, a significant difference (p < 0.05) was seen in pre-simulator assessment scores, and no significant difference in Likert scale assessment scores was seen.

CONCLUSIONS

This study demonstrated a new VEST educational module. Consistently high Likert assessment scores showed that users felt that the VEST module helped their understanding of dispersive electrode placement. Additionally, the study reflected a potential knowledge deficit in the safe use of dispersive electrodes in the surgical community, also demonstrating that even some exposure to the FUSE curriculum developed by SAGES provides increased awareness about dispersive electrode use.

Anaesthetic management of pregnant patients with cardiac implantable electronic devices: case reports and review

Heart disease is a leading cause of maternal mortality and morbidity. Pregnant women with structural, conduction or degenerative cardiac disease who require rhythm control or who are at high risk of sudden cardiac death may carry a cardiac implantable electronic device or may occasionally require the insertion of one during their pregnancy. These women are now encountered more frequently in clinical practice, and it is essential that a multidisciplinary approach, beginning from the early antenatal phase, be adopted in their counselling and management. Contemporary cardiac rhythm control devices are a constantly evolving technology with increasingly sophisticated features; anaesthetists should therefore have an adequate understanding of the principles of their operation and the special considerations for their use, in order to enable their safe management in the peripartum period. Of particular importance is the potential adverse effect of electromagnetic interference, which may cause device malfunction or damage, and the precautions required to reduce this risk. The ultimate goal in the management of this patient subgroup is to minimise the disruption to cardiovascular physiology that may occur near the time of labour and delivery and to control the factors that impact on device integrity and function. We present the ante- and peripartum management of two pregnant women with an implantable cardioverter-defibrillator, followed by a review and update of the anaesthetic management of parturients with cardiac implantable electronic devices.

Safety and interaction of patients with implantable cardiac defibrillators driving a hybrid vehicle

BACKGROUND

Electromagnetic interference (EMI) can affect the function of implantable cardioverter defibrillators (ICD). Hybrid electric vehicles (HEV) have increased popularity and are a potential source of EMI. Little is known about the in vivo effects of EMI generated by HEV on ICD.

OBJECTIVE

This study evaluated the in vivo interaction between EMI generated by HEV with ICD.

METHODS AND RESULTS

Thirty patients (73±9 y/o; 80% male) with stable ICD function were exposed to EMI generated by a Toyota Prius Hybrid®. The vehicle was lifted above the ground, allowing safe changes in engine rotation and consequent variations in electromagnetic emission. EMI was measured (NARDA STS® model EHP-50C) and expressed in A/m (magnetic), Volts/m (electrical), and Hertz (frequency). Six positions were evaluated: driver, front passenger, right and left back seats, outside, at the back and front of the car. Each position was evaluated at idle, 30 mph, 60 mph and variable speeds (acceleration-deceleration-brake). All ICD devices were continuously monitored during the study. The levels of EMI generated were low (highest mean levels: 2.09A/m at right back seat at 30 mph; and 3.5V/m at driver seat at variable speeds). No episode of oversensing or inadvertent change in ICD programming was observed.

CONCLUSION

It is safe for patients with ICD to interact with HEV. This is the first study to address this issue using an in vivo model. Further studies are necessary to evaluate the interaction of different models of HEV or electric engine with ICD or unipolar pacemakers.

Risk of electromagnetic interference induced by dental equipment on cardiac implantable electrical devices

Patients with cardiac implantable electrical devices should take special precautions when exposed to electromagnetic fields. Proximity to equipment used in clinical dentistry may cause interference. This study evaluated in vitro the risks associated with different types/makes of cardiac devices and types of dental equipment. Six electronic dental tools were tested on three implantable cardioverter defibrillators and three pacemakers made by different manufacturers. Overall, the risk of interference with the pacemakers was 37% lower than with the implantable cardioverter defibrillators. Regarding the types/makes of cardiac devices analysed, that from Boston Scientific had a five-fold greater risk of interference than did that from Biotronik [prevalence ratio (PR) = 5.58]; there was no difference between that from Biotronik and that from Medtronic. Among the dental equipment, the electric pulp tester had the greatest risk of inducing interference and therefore this device was used as the benchmark. The electronic apex locator (PR = 0.29), Periotest M (PR = 0.47), and the ultrasonic dental scaler (PR = 0.59) were less likely to induce interference than the electric pulp tester. The risk was lowest with the electronic apex locator. Pacemakers presented a lower risk of light to moderate interference (PR = 0.63). However, the risk of severe electromagnetic interference was 3.5 times higher with pacemakers than with implantable cardioverter defibrillators (PR = 3.47).

Clinical management of electromagnetic interferences in patients with pacemakers and implantable cardioverter-defibrillators: review of the literature and focus on magnetic resonance conditional devices

The number of cardiac implantable electronic devices (CIEDs) has greatly increased in the last 10 years. Many electronic devices used in daily activities generate electromagnetic interferences (EMIs) that can interact with CIEDs. In clinical practice, it is very important to know the potential sources of EMIs and their effect on CIEDs in order to understand how to manage or mitigate them. A very important source of EMI is magnetic resonance (MR), which is considered nowadays the diagnostic gold standard for different anatomical districts. In this review, we focused on the effects of EMI on CIEDs and on the clinical management. Moreover, we made a clarification about MR and CIEDs.In patients with CIEDs, EMIs may cause potentially serious and even life-threatening complications (inappropriate shocks, device malfunctions, inhibition of pacing in pacemaker-dependent patients) and may rarely dictate device replacement. The association of inappropriate shocks with increased mortality highlights the importance of minimizing the occurrence of EMI. Adequate advice and recommendations about the correct management of EMIs in patients with CIEDs are required to avoid all complications during hospitalization and in daily life. Furthermore, the article focused on actual management about MR and CIEDs.

Electromagnetic interference of endodontic equipments with cardiovascular implantable electronic device

OBJECTIVES

Assess the electromagnetic interference (EMI) of endodontic equipment with cardiovascular implantable electronic devices (CIEDs) and related factors.

METHODS

The laser device, electronic apex locators (EAL), optical microscope, endodontic rotary motors, gutta-percha heat carrier (GH), gutta-percha gun and ultrasonic device were tested next to CIEDs (Medtronic and Biotronik) with varied sensitivity settings and distances. CIEDs were immersed in a saline solution to simulate the electrical resistence of the human body. The endodontic equipment was tested in both horizontal and vertical positions in relation to the components of the CIED. The tests were performed on a dental chair in order to assess the cumulative effect of electromagnetic fields.

RESULTS

It was found no EMI with the Biotronik pacemaker. EALs caused EMI with Medtronic PM at a 2 cm distance, with the NSK(®) EAL also affecting the Medtronic defibrillator. GH caused EMI at 2 cm and 5 cm from the Medtronic defibrillator. EMI occurred when devices were horizontally positioned to the CIED. In the majority of the cases, EMI occurred when the pacemaker was set to maximum sensitivity. There was cumulative effect of electromagnetic fields between GH and dental chair.

CONCLUSIONS

EALs and GH caused EMI which ranged according to type and sensitivity setting of the CIEDs and the distance. However, no endodontic equipment caused permanent damage to the CIED. The use of GH caused a cumulative effect of electromagnetic fields. It suggests that during the treatment of patients with CIEDs, only the necessary equipments should be kept turned on.

CLINICAL RELEVANCE

Patients with CIEDs may be subject to EMI from electronic equipment used in dental offices, as they remain turned on throughout the treatment. This is the first article assessing the cumulative effect of electromagnetic fields.

Possible Influences of Spark Discharges on Cardiac Pacemakers

Exposure to spark discharges may occur beneath high voltage transmission lines when contact is initiated with a conductive object (such as a motor vehicle) with the spark discharge mediated by the ambient electric field from the line. The objective of this study was to assess whether such exposures could interfere with the normal functioning of implanted cardiac pacemakers (PMs). The experiment consisted of PMs implanted in a human-sized phantom and then exposed to spark discharge through an upper extremity. A circuit was designed that produced spark discharges between two spherical electrodes fed to the phantom's left hand. The circuit was set to deliver a single discharge per half cycle (every 10 ms) about 10 μs in duration with a peak current of 1.2-1.3 A, thus simulating conditions under a 400-kV power line operating at 50 Hz. Of 29 PMs acquired, all were tested in unipolar configuration and 20 in bipolar configuration with exposure consisting of 2 min of continuous exposure (one unit was exposed for 1 min). No interference was observed in bipolar configuration. One unit in unipolar configuration incorrectly identified ventricular extra systoles (more than 400 beats min(-1)) for 2 s. The use of unipolar configuration in new implants is extremely rare, thus further minimizing the risk of interference with the passage of time. Replication of this study and, if safety for human subjects can be assured, future testing of human subjects is also advisable.

Capacity of dental equipment to interfere with cardiac implantable electrical devices

Patients with cardiac implantable electrical devices should take precautions when exposed to electromagnetic fields. Possible interference as a result of proximity to electromagnets or electricity flow from electronic tools employed in clinical odontology remains controversial. The objective of this study was to examine in vitro the capacity of dental equipment to provoke electromagnetic interference in pacemakers and implantable cardioverter defibrillators. Six electronic dental instruments were tested on three implantable cardioverter defibrillators and three pacemakers from different manufacturers. A simulator model, submerged in physiological saline, with elements that reproduced life-size anatomic structures was used. The instruments were analyzed at differing distances and for different time periods of application. The dental instruments studied displayed significant differences in their capacity to trigger electromagnetic interference. Significant differences in the quantity of registered interference were observed with respect to the variables manufacturer, type of cardiac implant, and application distance but not with the variable time of application. The electronic dental equipment tested at a clinical application distance (20 cm) provoked only slight interference in the pacemakers and implantable cardioverter defibrillators employed, irrespective of manufacturer.

Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients

Background

Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle.

Objectives

To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs.

Methods

In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 – 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices.

Results

The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

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.

Implantable cardioverter defibrillator during laser transurethral resection of the prostate

  Implantable cardioverter defibrillators have been instrumental in the health and safety of patients who are at increased risk of sudden death by ventricular tachycardia or fibrillation. Consensus on the perioperative management of cardiovascular implantable electronic devices has suggested that certain surgical interventions (including transurethral resection of the prostate) may interfere with the sensing capability of the device, thereby resulting in unforeseen adverse outcomes. However, improvements in the implantable cardioverter defibrillators have made it less susceptible to surgical interference. In addition, current guidelines recommend deactivation of the implantable cardioverter defibrillators to an asynchronous mode prior to most surgical interventions. We present the first two case reports in which implantable cardioverter defibrillators were not deactivated prior to GreenLight 180-W XPS laser-guided transurethral resection of the prostate. We left the implantable cardioverter defibrillators activated to allow them to detect and treat lethal arrhythmias by direct rather than extrinsic cardioversion. There was no cardiac arrhythmia incident in these two cases. Laser technology is not a documented source of electromagnetic interference in patients with implantable cardioverter defibrillators. There is no current evidence that links lasers to implantable cardioverter defibrillators malfunction. With increasing numbers of patients with implantable cardioverter defibrillators undergoing many different laser surgical procedures, further studies are warranted to analyze in depth the effects of laser therapy on implantable cardioverter defibrillators function and update in current guidelines.

Innovations in heart rhythm disturbances: cardiac electrophysiology, arrhythmias, and cardiac pacing

This article reviews the most relevant articles published in 2012 in the field of arrhythmias, on subjects that include clinical arrhythmology, ablation, cardiac pacing, and the genetics of sudden cardiac death.

Electrosurgery in patients with implantable electronic cardiac devices (pacemakers and defibrillators)

The electrosurgical unit is a very useful tool widely used in dermatology to treat benign and malignant skin lesions and to achieve hemostasis during surgery. However, precautions are required when this technique is used in patients with implantable electronic cardiac devices (IECD), such as pacemakers and defibrillators, because electromagnetic interference produced by the tool may cause such devices to malfunction. Before using electrosurgery in patients with IECDs, it is essential to ascertain the type of implanted device and the patient's level of dependence on it. The location of the skin lesion to be treated with respect to the device should also be assessed. Bipolar pacemakers are more resistant to interference. Appropriate monitoring and the use of bipolar forceps are recommended.

Forces on cardiac implantable electronic devices during remote magnetic navigation

BACKGROUND

Remote magnetic navigation systems are used for catheter navigation in cardiac electrophysiological ablation procedures. In this setting, ferromagnetic particles will be moved by changes in the magnetic field. It is unknown to what extent cardiac implantable electronic devices (CIED) are affected by the magnetic field when using magnetic navigation, and whether these forces may exceed the limit of 5 N that is set forth by German and European norms for implanted electrodes.

METHODS

A total of 121 rhythm devices were examined in a magnetic field of 0.1 T using the NIOBE II(®) Magnetic Navigation System (Stereotaxis, St. Louis, USA). Forces acting on the devices were measured with the force measurement tool Futek LRF 400 (Futek Advanced Sensor Technology Inc., Irvine, CA, USA). A standardized protocol of different movements of the magnetic field including all three dimensions was performed and maximal forces on the CIED were assessed.

RESULTS

Out of 121 devices, 78 different pacemakers (54 different model families from 11 manufacturers) and 43 different cardioverter-defibrillators (26 different model families from 6) were examined. The mean force that could be observed was 0.33 ± 0.13 N for pacemakers (range 0.16-1.12 N) and 1.05 ± 0.11 N for cardioverter-defibrillators (range 0.86-1.38 N) when exposed to the magnetic field.

CONCLUSION

Exposure of pacemakers or implantable cardioverter-defibrillators to a magnetic field of 0.1 T does not result in a force exceeding the regulatory demanded 5 N that could damage the connected leads.