[Hyponatremia in heart failure: physiopathology and pharmacological approach]

Abstract

Hyponatremia is a well-known adverse prognostic factor in patients with chronic heart failure. The mechanisms linking hyponatremia with poor outcomes in these patients are not well understood and may be related to the presence of the abnormal management of water and neurohormonal activation seen in patients with chronic heart failure, which in turn are associated with a worse prognosis. Possibly, free-water retention exceeds the degree of sodium retention in chronic heart failure, which could partially explain the hyponatremia found in these patients. There are several therapeutic strategies for the management of hyponatremia in patients with chronic heart failure, including fluid restriction, high-dose diuretic administration and infusion of hypertonic saline, but none has been proven to be very effective. Recently, vasopressin antagonism through vasopressin receptor antagonists has opened up a new way of treating hyponatremia in these patients by enhancing aquaresis. Several agents are available but their possible impact on morbidity and mortality in patients with hyponatremia and chronic heart failure requires elucidation.