Fluid overload contributing to heart failure.

BACKGROUND In advanced heart failure, the compensatory responses to reduced cardiac output, in spite of fluid retention, lead to maladaptive consequences. METHODS We performed a Medline survey for fluid overload and heart failure as well as reviewing textbook chapters. RESULTS The increased sympathetic nervous system, renin-angiotensin-aldosterone system, and antidiuretic hormone stimulation and release lead to a vicious cycle--augmenting pre-load, contractility and after-load, as well as increased fluid overload. The elevated work load on an already failed cardio-circulatory system results in further deterioration. Plasma volume is usually increased in untreated patients with increased extracellular fluid. However, it may range from reduced to increased in treated patients. Currently, diuretics remain the initial first line of therapy. In refractory cases, restoring plasma volume and osmolality, by adding albumin or hypertonic saline solutions, neurohormonal antagonists such as vasopressin receptors antagonists, aldosterone antagonists, or administration of nesiritide, may help in overcoming fluid overload. CONCLUSION Exact measurement of plasma volume in various forms of heart failure and adjusting the treatment accordingly, establishing favourable and detrimental effects of various therapies, and introducing additional and new therapeutic options require further investigation.