Mechanisms of Diuresis for Acute Decompensated Heart Failure by Tolvaptan.

Tolvaptan, a vasopressin type 2 receptor antagonist, does not affect kidney circulation or cause worsening of renal function (WRF) in patients with acute decompensated heart failure (ADHF). Bioelectrical impedance analysis (BIA) can be used to evaluate intravascular volume by calculating the ratio of extracellular water (ECW) to intracellular water (ICW). There have been no reports examining the mechanisms of tolvaptan-induced diuresis using BIA.