I have read that it is possible for an i.v. injection of KCl to kill someone. On wikipedia it says that high doses can cause cardiac arrest and rapid death and that an extreme overdose is what is used for capital punishment by lethal injection. Other sites also comment on its effect on cardiac muscles.

I was wondering if anyone could please guide me in right direction the physiological details of why this occurs. I am currently studying membrane transport and potentials in class, but i cannot make the connection. (Does it have to do with the fact that K+ ions are resposible for resting potential?)


You are on the right track - think about K+ and the AV node in the heart and its role in systole and diastole. High potassium causes the heart to stop. Take a look at