Evidence that stun guns may stimulate the heart

[Celebration]

http://www.physorg.com/news128959244.html

On the eve of the British Columbia inquiry into the death of Robert Dziekanski, a review of scientific data in CMAJ (Canadian Medical Association Journal) finds that in some cases, stun guns may stimulate the heart in experimental models. This evidence is contrary to current views that stun guns only affect skeletal muscles.

“The frequency and the shape of the pulses generated by stun guns are designed to incapacitate the target by electrically overwhelming his or her control of these muscles,” state Dr. K. Nanthakumar and colleagues. “In principle, these pulses are designed to act only on skeletal muscles and to not affect internal organs such as the heart.” The evidence that stun guns do not stimulate the heart is based on “…theoretical studies suggest that stun guns cannot deliver the amount of energy required to stimulate the heart or cause ventricular fibrillation.”

Dr. Nanthakumar and collegues point out that most theoretical and some experimental studies reveal that cardiac stimulation does not occur with stun gun discharges. However, experimental studies on pigs by 3 independent groups of investigators found that “a stun gun discharge can stimulate the heart” depending on the location of the stun gun barbs. Barbs that are located such that they form a vector across the heart have greater effect than those focused on the abdomen. In one study, swine blood pressure was abruptly lost after discharge of a stun gun, and another study “reported the deaths of 2 animals caused by ventricular fibrillation immediately after the stun gun discharge….This suggests that sufficient current density was produced by the stun gun to stimulate the heart, which according to theory should not and could not occur.”

The researchers caution against applying data from pigs to humans, although “most of the basic mechanistic concepts in cardiac fibrillation and defibrillation are derived from animal studies, not humans.”

[LiberalFighter]

1. How many cops would be willing to be a guinea pig with the

target creating that vector including the heart?

[Fire_Medic_Dave]

2. Difficult to get the barbs to attach in the right location to achieve that vector.

The best way to create this vector is to attach one barb to the front of the chest above the heart and one barb to the back directly opposite the other barb. Much like the pads on defibrillators. I guess it wouldn't be impossible. Typically there are other factors involved in taser related deaths, in my town 2 people have died after running from police and being tasered. Both had extremely high levels of cocaine in their systems. I'm not ruling out the possibility that tasers could do what is stated in this article just that it would be extremely rare to replicate the conditions stated. It would also be extremely hard to blame the tasers exclusively in suspects who have high levels of drug in their systems. One factor that may not have been considered is metabolic acidosis. Let's say a suspect who has used illegal drugs runs away from the police for a mile, then fights with a police dog. Both of which would create large amounts of lactic acid in someone who hadn't trained for such an event. The taser would then cause skeletal muscle contraction on a huge scale this contraction would surely stimulate the muscle to contract at an anaerobic rate and release that much more lactic acid into the body which might cause metabolic acidosis, which can and will cause ventricular fibrillation and other types of cardiac arrest. I'll post this hypothesis by itself and see what kind of feedback we get. May be interesting.

David

[dropkickpa]

3. Not quite

Studies have shown that the 3 recommend placement positions of defibrillator electrodes, anterior-apex, apex-posterior (the positioning you note as most effective), and anterior-posterior are equally effective in emergency situations, which would most closely mimic the use of a taser (for pecing purposes, apex-posterior is preferred, but that doesn't apply when comparing usage to tasers).

http://linkinghub.elsevier.com/retrieve/pii/S0300957298000501

With a taser, it is quite likely that a torso aimed hit can acheive placement that is similar to effective defibrillation placement. With no ability to evaluate if a person is at higher-risk due to drug use or undiagnosed (or diagnosed, even) heart issues, I think it is a dangerous instrument. Police are constantly reassured by manufacturers and such that the device is perfectly safe to use, which I think leads many to use them quicker than they would if they were better informed about potential risks.

[Fire_Medic_Dave]

4. I said it would be difficult.

You would almost never get apex-posterior or anterior-posterior with a taser. So anterior-apex would be the most likely but the left arm would likely get in the way of getting the placement you need for the ideal vector. I would also argue that anterior-apex has been shown to be the least preferred positioning of the three for defibrillation. I do believe that tasers are over used and should only be used when the next step is shooting them. Having said that billy clubs and blackjacks killed a lot of people with closed head injuries in the years before the taser. I believe there are other factors involved. We have another thread going in the Guns Forum and another one in the health forum. I'd like your input.

David