Extracellular hydration, cardiovascular risk, and the interstitium: a three-dimensional view.

Volume expansion is a major contributor to poor cardiovascular outcomes in kidney disease. The relationship of extracellular volume (ECV) overload to cardiovascular changes in chronic kidney disease (CKD) remains speculative. Recent studies are challenging traditional concepts and providing new insight into mechanisms and the relationship of ECV to cardiovascular health. A dynamic role of the extracellular interstitium in inducing cardiovascular risk is emerging in CKD.