Pathophysiology of edema in congestive heart failure.

Congestive heart failure is one of the most important causes of peripheral edema seen in clinical practice. Edema in congestive heart failure is the result of the activation of a series of humoral and neurohumoral mechanisms that promote sodium and water reabsorption by the kidneys and expansion of the extracellular fluid. These mechanisms, in concert with abnormal Starling forces such as increased venous capillary pressure and decreased plasma oncotic pressure, promote fluid extravasation and edema formation. The management of edema in congestive heart failure is designed to improve cardiac function and to inhibit the hormonal and neurohumoral pathways that promote edema. The combination of diuretics and vasodilators or angiotensin converting enzyme inhibitors and, in some cases, cardiac inotropic agents is highly effective in achieving these goals and providing significant symptomatic improvement in patients with edema secondary to congestive heart failure.