Hyponatremia in heart failure: not just 135 to 145.

One of the most frequent in-hospital electrolyte disturbances is hyponatremia. Hyponatremia in heart failure (HF) is mainly associated with hypervolemia resulting from activation of baroreceptor-mediated hormones, such as arginine vasopressin (AVP), renin-angiotensin-aldosterone system, and catecholamines. Various electrolyte imbalance can occur as heart failure progress. The goal of this review was to outline the current literature on hyponatremia in HF patients.