Sodium from drinking water as an unsuspected cause of cardiac decompensation.

Abstract

A survey of 300 samples of drinking water from Southern Alberta analyzed for sodium content showed that a considerable proportion of well waters contain very high sodium levels, ranging up to 420 mg. per cent (4,200 ppm.). Two instances of recurrent episodes of heart failure at home, which ceased after substitution of a low- for unsuspected high-sodium water supplies, are described. The sodium is present in soils derived from underlying marine deposits of seas that covered the whole of the North American plains in ancient times. It is not readily recognizable by taste, especially as sulfate, and may cause darkening of soil so that its presence remains quite unsuspected. Tasteless sodium in water forms a source of perplexing decompensation in otherwise well-controlled heart disease. The features of the terrain that lead to high sodium content in water supplies are described to alert physicians to similar possibilities in their own regions.