Managing Hyponatremia in Advanced Heart Failure

Hyponatremia is present in over 20% of patients admitted to hospital with heart failure, and is associated with poor short- and long-term outcomes. There are two major pathogenic mechanisms of hyponatremia in heart failure: volume overload with excessive secretion of arginine vasopressin (AVP), which is a result of reduction in cardiac output and activation of intravascular volume sensor, and hypovolemic hyponatremia due to excessive use of diuretic agents. These two conditions require entirely opposite therapeutic approaches. Fluid restriction and loop diuretics are the mainstay treatments for hypervolemic hyponatremia in patients with heart failure. More recently, AVP antagonists have been proposed as a potentially promising treatment option. Other less established options include isolated extracorporeal ultrafiltration and combination therapy of hypertonic saline and loop diuretics. On the other hand, hypovolemic hyponatremia requires reduction in diuretic dosage and occasionally normal saline infusion. In this lecture, I shall summarize the current literature on the pathogenesis and management of hyponatremia in patients with heart failure.