Stun Guns, Like The Taser, Can Cause Cardiac Arrest

340-Most of us have probably laughed at someone on television getting shocked by a stun gun. They tense up and fall to the ground, seizing like an epileptic.  Once the shocking stops, the person gets up, seemingly unharmed.  The occasional, wet-your-pants complication, is classic humor!  All joking aside, there have been several reports showing the use of high voltage stun guns, like the Taser, (known in the medical world as electronic control devices { ECD’s}) can cause cardiac arrest.

Arguably, the most famous was published on April 20, 2012 in the American Heart Association’s journal, Circulation.  In it, Dr. Douglas Zipes, at the Indiana University School of Medicine, reports on cases involving loss of consciousness by people who had ECD’s used on them.  His conclusion was;

“ECD stimulation can cause cardiac electrical capture and provoke cardiac arrest due to ventricular tachycardia/ventricular fibrillation. After prolonged ventricular tachycardia/ventricular fibrillation without resuscitation, asystole develops.”

He then outlines the mechanisms involved leading to abnormal cardiac rhythms when ECD’s are used.

To better understand how ECD’s can cause your heart to stop beating, and why that knowledge will, most likely, never affect law enforcement’s use of them, let’s look at how the heart produces its own rhythm  and exactly how ECD’s can “capture” that rhythm and provoke cardiac arrest.

The heart is a two part pump, one part mechanical and the other electrical.  The mechanical squeeze of the heart happens because the electrical part of the heart shocks the muscle tissue, and it contracts.  Stick your finger in a light socket and you’ll get a great example of how electricity can cause your muscles to contract (actually don’t.  Our lawyers hate it when we make suggestions that can cause you harm).

heart 2The electrical impulse that shocks your heart normally comes from a grouping of specialized cells in the heart called your Sino-atrial node (SA node).  The impulse is created by an exchange of electrolytes across the SA node cells.  The electrolytes all have differing levels of charge.  Whether more positive or more negative, when separated by the cells membrane, the charge builds-up (called an action potential). Once that charge reaches a certain point, it discharges its power down the heart muscle.

The electrolytes involved with this bio-electricity are potassium, sodium and calcium.  Sodium and calcium generally reside outside the SA node cells.  Potassium generally lies within them.  Pressure from your bloodstream allows sodium to enter the cell, causing potassium to leave it.  Less potassium leaves the cell than sodium entering it.  The result is a continually growing positive charge.  Once that charge reaches a certain point, it opens up voltage regulated calcium channels and positively charged calcium now rushes into the cell.  This sudden increase in positive charge, creates a high enough action potential to be discharged down the heart muscle.  Ah, the pulse-producing wonders of chemistry in action.

When someone’s heart muscle is contracted by electricity, the muscle is said to be “captured” by that electricity.  Medical science has long known if you provide more electricity to the hearts muscle, than its own electrical impulse creates, you can over-ride that impulse and capture the muscle artificially.  This is the concept behind the treatment of several different types of abnormal heart rhythms the medical profession playfully calls “Edisons-medicine”.

shutterstock_128059580The treatment for the lethal heart rhythms, ventricular tachycardia (VT)/ventricular fibrillation (VF), mentioned by Dr. Zipes in his research paper, is to simply shock the heart with large amounts of electricity (between 150-200 joules in a bi-phasic defibrillator).  Should your heart beat too slowly (bradycardia), one treatment method is to capture the muscle with repeated shocks, causing the heart to beat faster, known as electrically pacing the heart.

There are some drawbacks to these electrical treatments.  After defibrillation, the heart might not go back to a normal pulse producing rhythm.  Should you capture the heart muscle with pacing, there is a chance, once you stop the treatment, the heart simply won’t have the necessary electrolyte exchange needed to produce an adequate pulse or blood pressure.  Another problem associated with capturing the heart muscle is, if you increase the rate too fast, you could send the person in to the aforementioned lethal heart rhythms VT and VF.

The problems associated with externally capturing the heart muscle, not allowing its own impulse to create muscle contraction, is how ECD’s cause cardiac arrest.

As you might expect, when Dr. Zipes published his paper, there was a large amount of controversy surrounding the topic.  After all, it was long reported by manufacturers of ECD’s, their products were non-lethal.  Stating, while the voltage associated with their use was high (usually between 20,000 and 150,000 volts) the amperage (around 3 milliamps) was too low to cause any permanent damage.

Law enforcement professionals were sometimes instructed to use the devices on themselves before they were qualified to use them on the public.   Cops everywhere began laughing at any new-guy that had to be qualified on the weapon.

Dr. Zipes was able to show that certain people are more susceptible to having this high voltage/low amperage electricity cause cardiac problems.  Specifically, those that have structural heart diseases, are taking medications or drugs that leave the heart irritable and susceptible to external stimulation, and those exposed to long or repeated shocks by an ECD.

shutterstock_139593233Placement of a ECD’s darts was also a contributing factor.  For any electrical impulse to capture a muscle, it must cross through that muscle.  This is why you see defibrillator paddles and pads being placed on either side of the heart when a doctor or paramedic attempts to externally shock a patient.  If a person had the ECD’s darts land on their chest, they are at greater risk of having that electricity pass through the hearts muscle.

As a result of this paper, clinical data and animal studies, some ECD manufacturers  have changed their stance on the non-lethal nature of their products.  Dr. Zipes states the question isn’t if ECD’s can cause cardiac arrest, but how often it happens.

In response to these concerns, Taser, Inc. has now warned their product can cause “heart rate, rhythm capture and cardiac arrest”.  Their lawyers estimate the risk around 1 in 100,000 applications.

Law enforcement officials from around the world have begun to notice and change their policies on the use of ECD’s.  In September of 2012, the Cincinnati Police Department changed its rules mandating “Frontal shots are prohibited except in situations of self-defense or defense of another”.   Most who have changed their policies are quick to point out, ECD’s protect and save countless lives every day.  The numbers of those saved drastically outweigh any risk associated with them.  They would be correct.

Amnesty International (arguably the biggest opponent of ECD’s) puts the estimated number of deaths in the United States, around 500, since 2001.  Depending on which publication you read, ECD’s are said to have saved around 75,000 lives and reduce the risk of injury to the suspect by 60%.

In the end, ECD’s can cause cardiac arrest.  To avoid being the 1 in 100,000 that dies from their use, try not to get hit in the chest.  Don’t use drugs that leave your heart susceptible to outside influence like cocaine, methamphetamines.  Don’t make the Police so mad they shock you numerous times, and don’t have structural heart problems.

Of course, if you want a 0% chance you will die from an ECD’s shock, don’t do anything that will cause law enforcement to pull the weapon to begin with.

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8 thoughts on “Stun Guns, Like The Taser, Can Cause Cardiac Arrest

Circulation has now published a detailed refutation of the Zipes case series which he had to update several times.

His report was a case series not a human study. Of importance is that a “case series” should report interesting associations and novel curiosities of medicine based on uncontrolled and anecdotal observations — it does not prove a cause-effect association. Dr Zipes’ article that published provides observational data from a series of eight cases provided to him in his disclosed role as a plaintiff’s expert during litigation of these cases.

Read this and it’s no wonder you didn’t add this to our references:

Read more from the various Circulation responses to Zipes as this is of note:

“Dr Zipes opines that various experimental studies support his conclusion that the TASER can cause cardiac capture and induce ventricular fibrillation or ventricular tachycardia in humans. The author cites porcine model studies in which electronic control devices were used to induce ventricular fibrillation or cardiac dysrhythmias in small swine in unique and unrealistic settings. Swine fibrillate more easily than humans, and their conduction system has a different anatomy, but even the studies that he cites did not conclude that electronic control devices cause ventricular fibrillation or dysrhythmias in humans.4,5 No X26 electronic control device studies with human subjects have demonstrated a single incident of cardiac capture or dysrhythmia without an exogenous pathway for conduction to the heart, such as pacemaker wires. In addition, more than a million volunteers have undergone TASER activations, many with the probes placed across the cardiac axis, and there has never been a loss of consciousness or death reported under these circumstances.”

“We appreciate the efforts of Dr Zipes in looking deeper into the important topic of sudden in-custody deaths, a very complex issue. There are many similar sudden deaths of subjects taken into custody who are not exposed to a TASER activation. It is our opinion that, although this article brings up questions and areas that need further research, this case series in and of itself does not support that TASERs are a substantial risk to the public.

As well as this: “In recognizing the scientific and societal importance of this article, we are also concerned that Zipes served as a legal expert in 100% of the series’ cases. We acknowledge his disclosure that he serves as an expert witness in plaintiff ECD death cases. It is our opinion that this role may have introduced bias into his interpretation of the facts in several of his article’s cases. Our belief is that some agencies may take Dr Zipes’ article as de facto science based on an American Heart Association imprimatur. This interpretation could result in the removal of ECDs from field use, setting officers back 30 years to use potentially more lethal force, with the possibility that lives will be unnecessarily lost and engendering increased litigation against police.”

Also, the voltage output on a human is approx 1340-2150 volts nowhere near what you cited.

How many of the 500 deaths you claim by Amnesty International actually listed the TASER CEW as causal, contributory or the nebulous “couldn’t be ruled out?” Check with them as they only cite approx. 60 – not 500 in reality. See the latest update on page 289 of the 2013 Amnesty International report where AI clearly states: “At least 42 people across 20 states died after being struck by police Tasers, bringing the total number of such deaths since 2001 to 540. Tasers have been listed as a cause or contributory factor in more than 60 deaths.”

Wait “more than 60” or is it 500? Perhaps the vast majority of those deaths had autopsies that exonerated the TASER from contribution or causality. Hmmm. Check with AI and get them on record as to the precise count.

@ Steve Tuttle- Thank you for your interest in our article. We here at The Medicine Journal appreciate all input we can get on any topic. We also understand that in medicine there can sometimes be conflicting reports and studies that say opposing things. In those cases, people must always look at the science objectively and form their own opinion. With this in mind we have several issues with your response: The study you pointed to, and apparently would rather have us site in our references, can be countered by numerous other studies saying the exact opposite. I point you to here;
And that was just the link your own study pointed us to in the first 5 minutes of looking.
We both looked at and understood all of the opposing studies presented before we wrote our article. The point of our article was that it is possible to cause cardiac arrest with ECD’s, not that it is either common, or appropriate to cease using them, because of it. We went out of our way to point out that while the possibility exists, law enforcement is right to use them to help save lives and reduce injuries to those they need to subdue.
One glaring problem with your argument is; your own legal counsel and company issued a statement in 2011 warning that ECD’s can cause “heart rate, Rhythm capture” and “cardiac arrest”. Your own legal counsel put the estimated number at around 1/100,000 applications. If you are now saying that your company would like to retract those statements, come out and tell the public they absolutely cannot cause cardiac arrest (and back it up with a confirming study), then we would gladly retract our article and rewrite it. The study you cited has only 1201 cases reviewed. How does that number in any way tell you ECD’s can’t cause cardiac arrest when the risk is at 1/100,000. You would have to evaluate 100,000 applications if you were to have a statistically significant result.
Also, if you have a problem with Amnesty International’s numbers, I suggest you take that up with them. We have no ties to that organization and as such, can only site the numbers they give us.
In the end sir, we understand why your organization would have a problem with any “bad-press” associated with their use. We do not feel our article in any way sheds a bad light on Tasers. We simply stated the possibility exists, and that even though it does, ECD’s save many more lives than they hurt. We look forward to any further comments you might have on this topic.

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  • Mr. Tuttle is the VIP of Strategic Communications at Taser International…so why wouldn’t he get on here and post a comment in response to this article. Drink more of the kool aid sir. Tasers can and do kill. The problem is it is not frequently enough that Taser really cares.

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