...and stun guns can cause heart attacks for those with pace makers. No non lethal weapon is one hundred percent non lethal.
Don't break the law & you have nothing to worry about.
Nit picking here but a myocardial infarction or heart attack is caused by reduced blood flow to a portion of the heart.
A stun gun may or may not affect the function of a pace maker, I have not seen evidence that it does, but it should not cause a heart attack.
Most of the death associated with stun gun use is also highly associated with stimulent use such as meth or cocaine. People on meth and cocaine also tend to drop dead strugling against their restraints, both in custody and when under full monitoring in an emergency room.
I have seen stats that stun guns are safer than pepper spray but the point of fact is that they are both orders of magnitude safer than being beat down or shot.