My sources indicate potassium depletion and resultant cardiac complications. In any case hypovolemic shock from dehydration will do the job from any of a number of specific mechanisms. Untreated, mortality can be around 50%, but proper medical care, as simple as rehydration with Oral Rehydration Therapy or IVs, can drop that dramatically.

That's why I recommend anyone interested in long term survival in a post-disaster situation or anything where third world type diseases might come calling after a breakdown of basic water and sanitation systems know the ORT formula or maybe lay in a supply of the premixed stuff.

Ingredients:

* one level teaspoon of salt
* eight level teaspoons of sugar
* one litre of clean drinking or boiled water and then cooled
5 cupfuls (each cup about 200 ml.)

Preparation Method:

* Stir the mixture till the salt and sugar dissolve.

One sample source for a commercially available premix