Hyponatremia in the setting of acute heart failure syndrome

Abstract

Hyponatremia is usually defined as a decrease in plasma sodium to a level ≤135 mEq/L. It is the most frequent electrolyte disorder occurring in hospitalized patients.1-3 Its actual incidence depends on the defined level of hyponatremia: 20% for natremia ≤136 mEq/L and 1% to 4% for natremia <130 mEq/L. This chapter discusses the pathophysiology, diagnosis and principles of treatment of hyponatremia, and suggests specific considerations for hyponatremia occurring in patients with heart failure. © 2008 Springer-Verlag London.