Effect of a Taser shot to the chest of a patient with an implantable defibrillator

Elektroschockdistanzwaffen Taser® X2 und T7

Die medizinische Beurteilung von Verletzungen und potenzieller todesursächlicher Relevanz einer Stromexposition durch eine Elektroschockdistanzwaffe beschränkt sich nicht allein auf die situativen Gegebenheiten und die morphologische Befunderhebung, sondern beinhaltet auch eine intensive Analyse polizeilicher Ermittlungen und die Auswertung von Zeugenaussagen sowie vorangegangener medizinischer Maßnahmen. Insbesondere bei zeitlich relevanter Nähe zwischen Exposition und Todeseintritt muss die Wirkung der übertragenen Stromimpulse in Zusammenhang mit der meist komplexen Einsatzsituation und der medizinischen Vorgeschichte des Geschädigten beurteilt werden. Ein detailliertes Wissen über die konkrete und auch abstrakte Wirkungsweise, Wirksamkeit und Risiken von Elektroschockdistanzwaffen ist hierfür unabdingbar.

Medical Care in a Police Intervention with Conducted Electrical Weapons: Zaragoza (Spain) Fire Department Protocol

In the last decade, conducted electrical weapons (CEWs) have become a new tool for law enforcement agencies as an alternative to firearms. They provide security in the intervention for both the police and the citizen and try to cause the least possible harm to the subject to immobilize.The health care providers who perform in joint actions with the police in which CEWs are used should be aware of how they work, risk groups, as well as the most frequent clinical effects associated with the application of electrical discharge, and the complications that can be produced according to the area of impact of the electrodes.For this purpose, the current medical literature was reviewed by consulting the main health care sciences database (PubMed) to determine the medical measures to be taken before, during, and after the use of these weapons. Also presented and shared is the Zaragoza (Spain) Fire Department protocol.

Inappropriate ICD Shock as a Result of TASER Discharge

Conducted energy weapon (commonly known as TASER) discharge in patients with implantable cardioverter-defibrillators is known to cause electromagnetic interference and inappropriate ventricular fibrillation sensing without delivery of implantable cardioverter-defibrillators therapy during conducted energy weapon application. We report the first known case of conducted energy weapon discharge resulting in inappropriate implantable cardioverter-defibrillators therapy. (Level of Difficulty: Beginner.)

Medical implications of Conducted Energy Devices in law enforcement

This study examines the medical implications of Conducted Energy Devices (CEDs) in law enforcement, of which TASER® is the brand most recognised. In order to develop understanding of TASER® use, this study undertook both a literature review and original research using data provided by a number of UK police forces. The comprehensive review of literature identified a range of injures, including both primary and secondary complications. Research was conducted into TASER® use in the United Kingdom using a number of data sets, including a retrospective study of some 60,000 uses of force. This data shows TASER® was only discharged on 18% of occasions it was drawn from the holster. The injuries sustained by both subjects and Police Officers associated with TASER® use were compared and it was found that fewer injuries, as a proportion of use, were associated with TASER® than use of Police Dogs, baton, irritant spray or physical confrontation. The data examined 948 discharges of TASER® and recorded 159 attendances at the Emergency Department as a result. Only three hospital admissions were identified. The paper concludes that the use of CEDs as a police use-of-force may be associated with injury; the overwhelming majority of such are classified as minor. Death or the more severe injuries described in the medical literature are rare and any deaths occurring within temporal proximity to the use of a CED should be investigated thoroughly and the presentation of the individual carefully recorded. The collection of post-incident data provides evidence to the relative operational safety of the TASER® by the UK Police; it is accepted by the police that no use-of-force option is risk free, however data provided showed a greater incidence of injury to both the officers and subjects, as a proportion of use, when baton, irritant spray or physical confrontation was used.

Electrical Stun Gun and Modern Implantable Cardiac Stimulators

The aim of the study is to investigate systematically the possible interactions between two types of stun guns and last-generation pacemakers and implantable defibrillators. Experimental measurements were performed on pacemakers and implantable defibrillators from five leading manufacturers, considering the effect of stun gun dart positioning, sensing modality, stun gun shock duration, and defibrillation energy level. More than 300 measurements were collected. No damage or permanent malfunction was observed in either pacemakers or implantable defibrillators. During the stun gun shock, most of the pacemakers entered into the noise reversion mode. However, complete inhibition of the pacing activity was also observed in some of the pacemakers and in all the implantable defibrillators. In implantable defibrillators, standard stun gun shock (duration 5 s) caused the detection of a shockable rhythm and the start of a charging cycle. Prolonged stun gun shocks (10-15 s) triggered the inappropriate delivery of defibrillation therapy in all the implantable defibrillators tested. Also in this case, no damage or permanent malfunction was observed. For pacemakers, in most cases, the stun guns caused them either to switch to the noise reversion mode or to exhibit partial or total pacing inhibition. For implantable defibrillators, in all cases, the stun guns triggered a ventricular fibrillation event detection. No risks resulted when the stun gun was used by a person wearing a pacemaker or an implantable defibrillator. This work provides novel and up-to-date evidence useful for the evaluation of risks to pacemaker/implantable defibrillator wearers due to stun guns.

Intracardiac electrocardiographic assessment of precordial TASER shocks in human subjects: A pilot study

BACKGROUND

Case reports of cardiac arrest in temporal proximity to Conducted Electrical Weapon(CEW) exposure raise legitimate concerns about this as a rare possibility. In this pilot study, we respectfully navigate the oversight and regulatory hurdles and demonstrate the intra-shock electrocardiographic effects of an intentional transcardiac CEW discharge using subcutaneous probes placed directly across the precordium of patients with a previously implanted intracardiac EKG sensing lead.

METHODS

Adults scheduled to undergo diagnostic EP studies or replacement of an implanted cardiac device were enrolled. Sterile subcutaneous electrodes were placed at the right sternoclavicular junction and the left lower costal margin at the midclavicular line. A standard police issue TASER Model X26 CEW was attached to the subcutaneous electrodes and a 5 s discharge was delivered. Continuous surface and intracardiac EKG monitoring was performed.

RESULTS

A total of 157 subjects were reviewed for possible inclusion and 21 were interviewed. Among these, 4 subjects agreed and completed the study protocol. All subjects tolerated the 5 s CEW discharge without clinical complications. There were no significant changes in mean heart rate or blood pressure. Interrogation of the devices after CEW discharge revealed no ventricular pacing, dysrhythmias, damage or interference with the implanted devices.

CONCLUSIONS

In this pilot study, we have successfully navigated the regulatory hurdles and demonstrated the feasibility of performing intracardiac EKG recording during intentional precordial CEW discharges in humans. While no CEW-associated dysrhythmias were noted, the size of this preliminary dataset precludes making conclusions about the risk of such events. Larger studies are warranted and should consider exploring variations of the CEW electrode position in relation to the cardiac silhouette.

Effects of external electrical and magnetic fields on pacemakers and defibrillators: from engineering principles to clinical practice

The overall risk of clinically significant adverse events related to EMI in recipients of CIEDs is very low. Therefore, no special precautions are needed when household appliances are used. Environmental and industrial sources of EMI are relatively safe when the exposure time is limited and distance from the CIEDs is maximized. The risk of EMI-induced events is highest within the hospital environment. Physician awareness of the possible interactions and methods to minimize them is warranted.

Electromagnetic interference and implanted cardiac devices: the nonmedical environment (part I)

The number of patients with cardiovascular implantable electronic devices (CIEDs), such as permanent pacemakers and implantable cardioverter-defibrillators, is dramatically rising due to an aging population and recent clinical trials showing benefits in mortality and morbidity. Coupled with this increase in the number of patients with CIEDs is the proliferation of technology that emits electromagnetic signals, which can potentially interfere with CIED function through electromagnetic interference (EMI). Despite continuous efforts of manufacturers to create "EMI-proof" CIEDs, adverse events from EMI still occur. Physicians caring for patients with CIEDs should be aware of potential sources of EMI and appropriate management options. This 2-part review aims to provide a contemporary overview of the current knowledge regarding risks attributable to EMI interactions from the most common nonmedical (Part I) and medical (Part II) sources.

TASER conducted electrical weapons and implanted pacemakers and defibrillators

INTRODUCTION

Conducted electrical weapons (CEW) have generated controversy in recent years regarding their effect on heart rhythm and on their suspected interaction with implanted devices such as the pacemakers and ICDs (implantable cardioverter defibrillators). We review the current evidence available on device interactions and pre-sent a new case series of 6 patients.

LITERATURE

We used the available case reports and animal studies on TASER or CEW related publications in PubMed.

CONCLUSION

Oversensing of TASER CEW discharges may cause noise reversion pacing in pacemakers and inappropriate detection of VF in ICDs. The nominal 5-second discharge is sufficiently short that neither clinically significant inhibition of bradycardia pacing nor inappropriate ICD shocks have been reported. Current evidence indicates that CEW discharges do not have adverse effects on pacemakers and ICDs.

Multi-organ effects of Conducted Electrical Weapons (CEW) -- a review

Since the introduction of the Conducted Electrical Weapons (CEW) several studies have been conducted and multiple reports have been published on safety of these devices from a medical point of view. Use of these devices in different situations and reported deaths attracts media attention and causes general anxiety around these devices. These devices have several limitations- such as rate of fire or maximum effective range in comparison to fire arms. Here we wish to review medical publications regarding the safety of these devices based on different systems.

Review article: Emergency Department implications of the TASER

The TASER is a conducted electricity device currently being introduced to the Australian and New Zealand police forces as an alternative to firearms in dealing with violent and dangerous individuals. It incapacitates the subject by delivering rapid pulses of electricity causing involuntary muscle contraction and pain. The use of this device might lead to cardiovascular, respiratory, biochemical, obstetric, ocular and traumatic sequelae. This article will summarize the current literature and propose assessment and management recommendations to guide emergency physicians who will be required to review these patients.

Atrial fibrillation after taser exposure in a previously healthy adolescent

We are reporting a previously healthy adolescent who developed atrial fibrillation after being tased. He has a structurally normal heart on echocardiogram, normal electrolyte level and thyroid function test results, and a urine toxicology screen positive for marijuana. The patient ultimately required external defibrillation to convert his cardiac rhythm to normal sinus rhythm and has had no recurrent arrhythmias since hospital discharge (approximately 1 year). This is the first reported case of atrial fibrillation developing after a Taser shot, occurring in an adolescent without other risk factors. This case illustrates the arrhythmogenic potential of a Taser in otherwise healthy young individuals, and further study of occurrence of Taser-induced arrhythmias is warranted.

Physiology and pathology of TASER electronic control devices

TASER ECDs (electronic control device) are small, battery powered, handheld devices. They deliver short duration, low energy pulses to stimulate motor neurons, causing transient paralysis. While the experience is painful, proper use of the device is rarely associated with significant side effects in spite of 1070 human worldwide exposures daily. In fact, there have been more than 780,000 training exposures and 630,000 field uses (total of over 1.4 million human uses) without any credible evidence of a resulting cardiac arrhythmia. In this article we describe the mechanisms by which the device operates, and review possible morbidities.

Evaluation of the skin-to-heart distance in the standing adult by two-dimensional echocardiography

BACKGROUND

An electromuscular incapacitating device (EMD) delivers pulses of high-voltage electricity, causing strong muscle contraction. Data from a pig model suggest that an EMD dart tip placed within 17 mm of the epicardial surface can cause ventricular fibrillation. The current study estimates minimum skin-to-heart distance in the adult, to determine whether individuals might be at risk for ventricular fibrillation from an EMD.

METHODS

We performed 2-dimensional echocardiograms in 150 standing adults in the parasternal, apical, and subcostal views. From each view, the shortest linear skin-to-heart distance was measured.

RESULTS

Average skin-to-heart distances were: parasternal 32.1 +/- 7.9 mm; apical 31.3 +/- 11.3 mm; and subcostal 70.8 +/- 22.3 mm. There were 9 (6%) individuals with a skin-to-heart distance less than or equal to 17 mm. The skin-to-heart distance was significantly correlated with body mass index: parasternal r = 0.57, apical r = 0.55 (P < .0001).

CONCLUSIONS

An EMD dart penetrating the skin directly over the heart might put individuals at risk for ventricular fibrillation.

Cardiac Monitoring of Human Subjects Exposed to the Taser®

The Taser (TASER International, Scottsdale, AZ) is a high-voltage, low-amperage device used by many law enforcement agencies. Our objective in this study was to evaluate for rhythm changes utilizing cardiac monitoring during deployment of the Taser on volunteers. A prospective, observational study evaluated law enforcement personnel who had continuous electrocardiographic monitoring immediately before, during, and after having a voluntary exposure to the Taser X-26. Changes in cardiac rate, rhythm, ectopy, morphology, and conduction intervals were measured. A total of 105 subjects were evaluated. The mean shock duration was 3.0 s (range 0.9-5 s). Mean heart rate increased 15 beats/min (95% CI 12.6-18.3), from 122 beats/min before shock to 137 beats/min immediately after shock. One subject had a single premature ventricular contraction both before and after the shock, but no other subject developed ectopy or dysrhythmia. Poor inter-rater agreement prevented determination of the overall effect of shock on conduction intervals. However, several interpretable tracings demonstrated change in QT duration-either shortening or prolongation after shock. Human subjects exposed to a brief shock from the Taser developed significant increases in heart rate, but there were no cardiac dysrhythmias or morphologic changes. Alterations in the QT interval were observed in some subjects but their true incidence and clinical significance are unknown.

Taser-induced rapid ventricular myocardial capture demonstrated by pacemaker intracardiac electrograms

INTRODUCTION

A Taser weapon is designed to incapacitate violent individuals by causing temporary neuromuscular paralysis due to current application. We report the first case of a Taser application in a person with a dual-chamber pacemaker demonstrating evidence of Taser-induced myocardial capture.

METHODS AND RESULTS

Device interrogation was performed in a 53-year-old man with a dual-chamber pacemaker who had received a Taser shot consisting of two barbs delivered simultaneously. Assessment of pacemaker function after Taser application demonstrated normal sensing, pacing thresholds, and lead impedances. Stored event data revealed two high ventricular rate episodes corresponding to the exact time of the Taser application.

CONCLUSIONS

This report describes the first human case of ventricular myocardial capture at a rapid rate resulting from a Taser application. This raises the issue as to whether conducted energy devices can cause primary myocardial capture or capture only in association with cardiac devices providing a preferential pathway of conduction to the myocardium.

Do electrical stun guns (TASER-X26) affect the functional integrity of implantable pacemakers and defibrillators?

AIMS

High voltage electric current can adversely affect pacemakers (PM) and implantable cardioverter-defibrillator (ICD). The standard shock from an electrical stun gun (TASER- X26, TASER International, Scottsdale, AZ) consists of a 5-s long application of high voltage, low current pulses at 19 pulses per second. Its effect on the functional integrity of PM and ICDs is unknown.

METHODS AND RESULTS

We tested the functional integrity of nine PMs and seven ICDs in a swine model after a standard stun gun shock. A transvenous, dual coil, bi-polar ICD lead (St Jude-SP01) and a PM lead were placed in the right ventricular (RV) apex and connected to pulse generators buried in the pre-pectoral pocket. The two darts were placed at the sternal notch (SN) and apex of the heart bracketing the device pocket. Standard neuromuscular incapacitating (NMI) discharges were delivered. Functional parameters of the devices and leads were checked before and after the shocks. The mean pacing thresholds, sensing thresholds, pacing impedances, and defibrillation coil impedances of the ICD lead were similar before and after the shocks. Similarly, pacing thresholds, sensing thresholds, and impedances of the PM lead were not significantly different before and after the shocks. No significant change was noted in battery voltage and projected longevity. Implantable cardioverter-defibrillator generators detected the NMI impulses at a mean cycle length of 176 +/- 20 ms with detection to charge time of 5.9 +/- 1.5 s. Shock delivery was aborted in all tests as tachycardia detection abruptly terminated at the end of the 5 s NMI application. None of the devices exhibited power on reset (POR), elective replacement indicator (ERI), or noise mode behaviour after the shock.

CONCLUSION

Pacemakers and ICD generators and leads functions were not affected by the tested standard 5 s stun gun shocks.

Concerns about the use of TASERs on people with mental illness in New Zealand

The introduction of TASERs into New Zealand policing, and especially the identification of people in mental health crisis as one potential target group, raises serious concerns for mental health nurses. TASERs have been associated with over 150 deaths internationally, and raise the possibility of additional trauma for people in mental health crisis.