Now, nobody should take what I'm gonna say as gospel (ahem, myco, looking at you bud

) I'm simply playing devils advocate and voicing my opinions here... Anywho, I see no doses listed and whatever mitrgagynine and friends are causing it is "dose dependant". Who's to say that the amount of alkaloid in an average dose of kratom is enough to produce any of these effects? When there have been no recorded deaths by cardiac arrest in a person with kratom in their system, the cause of death associated with arrhythmias, there are no doses listed, and these issues are dose dependant, it's hard for me to take this as groundbreaking news here.
If you've got the money it's not hard to fund a study searching for negatives, just megadose isolated chemicals not list the dose... that is
not to say that's what's going on here though. These arrhythmias may be very real issues but that still doesn't prove that these are issues you're average kratom user will face, nobody is isolating chemicals and (I assume?) IV'ing them. Any kratom user will confirm how self limiting the plant is when it comes down to how much you can ingest.
When the conclusions say that mitrgagynine may potentiate Torada De Pointes that seems to insinuate that you have to be susceptable to this in the first place right? I'm not sure what that's about. Also, the deaths from mitragynine that are said to be from cardiac arrest are reffering to the isolated chemical. There have been no deaths from acute cardiac arrest linked to kratom. Being that the dose is what makes a poison I'm not convinced that these arrhythmias will ever be a problem for the average user. You can easily isolate thc from cannabis and induce a death if you shoot someone up with a megadose but we all know that you're not going to kill yourself by ingesting cannabis itself. There's just not nearly enough to go on and it's another one of those studies that brings up more questions than answers.
As always always it's best to err on the side of caution but quite frankly this isn't cut and dry enough to make
me think twice about taking it. Nobody should make their choice based on my words though, that's your responsibility to draw your own conclusions. What I can say is that I've had 5 or 6 (that's correct, about 5-6) EKG's and a treadmill stress test done in the last two years, been using kratom for over 5 years, and none showed any arrhythmia's... all were done under the influence of kratom. In the hospital I was also hooked up to one of those machines that constantly monitors your heart rythym, nothing. I do have structural damage to my valves but that's another story,
heavy abuse of strong 5-HT2B agonists will do that... and the damage done by these drugs is very unique. I'm not encouraging anyone to blow the study off, but this isn't gonna change my views or usage.
Just want to bring this too everyones attention:
http://www.ncbi.nlm.nih.gov/pubmed/25535742
Kratom may cause the life threatening arrythmia torsades de pointes
To be fair the results of the study say that mitragynine may potentiate Torsade de Pointes rather than cause it, whether it was just poor choice of words I'm not sure...