Do Electrical Stun Guns (TASER-X26 ®) Affect the Functional Integrity of
Implantable Pacemakers and Defibrillators?
Lakkireddy D, MD*; Wallick D, PhD†; Atul Khasnis MD; Antenacci J, RN BSN†; Kowalewski W, BA†; Martin D, MD†; Chung M, MD†; Wazni O, MD†;
Patel D, DO†; Vanga SR, MBBS‡; Natale A, MD†; Tchou P, MD†
*The Richard and Annette Bloch Heart Rhythm Center, Mid America Cardiology @ University of Kansas Hospital, Kansas City, KS;
†Cleveland Clinic, Cleveland OH; ‡St. Luke’s Hospital, Chesterfield, MO.
Background & Objective
•The use of neuromuscular incapacitation devices (NMIDs) is gaining
popularity over traditional lethal and non-lethal weapons by law
enforcement personnel internationally
• Implantable cardiac devices are susceptible to malfunction as a result
of electromagnetic interference (EMI). EMI can result in many
undesirable consequences, including damage to internal circuitry,
oversensing, undersensing, failure to pace, failure to capture, power on
reset (POR), triggering of elective replacement indicators (ERI) and
inappropriate defibrillation therapy

Results

Methods
Electrical stun device: The TASER® X26 is a 26-watt pistol-like device that
shoots two tethered darts and delivers up to 6000 volts (typical output about 1500
volts) of peak electrical potential in rapid pulses (19 pulses per second) over 5
seconds. The average net current is < 2 mA (I = Q/t = 100 µC/ (1/19s) = 1.9
mA, i.e <2 mA). The energy per pulse is about 70 mJ so the average output
power is < 1.5 W (P = W/t = 70 mJ/ (1/19s) = 1.33 W, i.e < 1.5 W).

Table 1: Pre and post shock evaluations of ICD systems

Make

Model

R

PT
Pre

DFCI DCL

LI

CT

Pre Post Pre Post

Post

Vitality DS

3.20

3.20

9.3

7.1 1.4@0.5

0.4@0.5

394

369

54

52

178

7.6

Guidant

Ventak MS

2.58

2.58

8.0

7.8 0.2@0.5 0.2@0.5

389

397

50

49

160

5.4

Guidant

Vitality DS

3.19

3.19

8.0

6.9 0.2@0.5 0.2@0.5

352

354

50

52

154

4.9

2.93

2.93

8.0

7.0 0.2@0.5 0.2@0.5

367

348

54

51

169

8.4

5.16

5.16

7.5

7.5 2.0@0.4 2.0@0.4

500

474

59

59

210

5.6

3.10

3.10

4.2

4.9 0.2@0.5 2.2@0.5

395

380

44

44

196

5.2

3.00

3.00

4.3

4.4 0.2@0.5 1.0@0.5

355

375

46

46

165

4.3

Guidant
Medtronic

•The effect of a standard shock from an electrical stun gun (TASERX26 ®, TASER International, Scottsdale AZ) on the functional integrity
of PMs and ICDs is unknown.

Bat V

Pre Post Pre Post
Guidant

7273

The mean pacing thresholds (PT), sensing thresholds (ST), pacing impedances and
defibrillation coil impedances of the ICD lead were similar before and after the shocks.
Similarly, PTs, STs, 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. ICD generators
detected the NMI impulses at a mean cycle length of 176+20ms with detection to charge
time of 5.9+1.5 seconds. Shock delivery was aborted in all tests as tachycardia detection
abruptly terminated at the end of the 5 second NMI application. None of the devices
exhibited power on reset (POR), elective replacement indicator (ERI) or noise mode
behavior after the shock.
ICD memory record of NMI discharge

St. Jude
St. Jude

•This study evaluates the immediate effects of NMID discharges on the
function of implanted cardiac PMs and ICDs.

Photon VR

Mean

3.31 3.31 7.0 6.5

0.6

0.9 393 385 51

SD

0.84 0.84 2.0 1.3

0.8

0.9

50 42

5

50 176 5.9
5

20 1.5

Table 2: Pre and post shock evaluations of pacemaker systems
Device testing: A prepectoral subcutaneous pocket that lies in between the darts
was created to house the generator. A 70 cm long, transvenous, bipolar, dual-coil,
St. Jude SPLTM cardioverter defibrillator lead (Model # SP-01, St. Jude
Medical, St. Paul, MN) and a 52 cm long St. Jude Isoflex (Model # 1648T, Jude
Medical, St. Paul, MN) transvenous, bipolar, passive-fixation, pace-sense lead
were placed in the right ventricle through the left internal jugular vein. Both
leads were tunneled from the neck into the pre-pectoral pocket and were
connected to a pacemaker (9) or ICD generator (7)
Discharges were delivered through the darts to the above-mentioned sites. All the
devices were tested in a single animal and each of the devices was tested with
three standard NMI discharges of 5 seconds duration each.

Make

Model

Bat V
R
Pre Post Pre Post

PT
Pre

LI
Post

Pre

Post

Medtronic

Insync

2.95

2.95

8.0

8.0 0.5@0.5

0.5@0.5

422

409

St. Jude

Enpulse

2.75

2.75

5.6

5.6 0.25@0.52

0.75@0.52

417

423

St. Jude

Identity DR

2.73

2.71

5.0

5.3 0.25@0.5

0.25@0.5

334

356

St. Jude

Affinity DR

2.75

2.75

7.0

7.0 0.25@0.8

0.25@0.8

374

374

St. Jude

Integrity AF

2.75

2.76

6.2

6.4 0.25@0.4

0.25@0.4

401

383

St. Jude

Affinity DR

2.76

2.76

7.0

7.0 0.25@0.5

373

403

Medtronic

Insync

2.77

2.77

8.0

8.0 0.5@0.5

0.5@0.5

426

422

2.78

2.76

5.7

5.3 0.3@0.5

0.3@0.5

410

400

2.85

5.1

380

380

Guidant
Guidant

Pulsar Max

2.86

5.8 0.2@0.4

0.25@0.5

0.3@0.4

Pacing and sensing thresholds as well as pacing and shocking coil impedances
were determined before and after each of the three NMI discharges. The average
value was considered for final analysis.

Mean
SD

Defibrillation threshold testing (DFT) was not done. The generators were monitored for
abnormal behavior, including oversensing, undersensing, failure to pace, failure to capture,
power on reset (POR), elective replacement indicator (ERI) and inappropriate defibrillation
therapy.

Pre ‐ Preshock, Post ‐ Postshock, Bat V– Battery voltage in V, R – R waves sensing threshold in mV, PT 
– pacing threshold in V @ms, LI –Lead impedance in Ohms, DFCI – Defibrillation Coil Impedance, DCL 
– Detected cycle length in milliseconds, CT – Charge time in seconds.

2.79
0.07

2.78 6.40
0.07 1.15

6.48
1.07

0.3
0.1

0.4
0.2

393.00 394.44
30.15
22.71

This interrogated electrogram strip from the ICD memory after the NMI application shows onset of rapid rate detection with initiation of the
application. The device responds by starting to charge its capacitors. However, prior to shock delivery, the application is terminated and
the device aborts the shock delivery. Note that detected cycle length corresponds best to the detected NMI pulses rather than the ventricular
electrograms even though accelerated ventricular capture can be appreciated visually at cycle lengths around 240 ms.

Conclusions
• NMI discharge does not affect the short-term functional integrity of implantable
pacemakers and defibrillators even when the darts are placed in a manner to sandwich
the generator.
• The standard NMI application duration of 5 seconds should not trigger an ICD shock
in devices programmed to a non-committed shock delivery mode.

This study was funded educational grant from TASER International, Scottsdale, AZ. The funding source had no input on the study design, organization, results and
manuscript preparation. None of the contributing authors have any kind of financial or any other conflict of interest with the funding source.