Randomized, Double-Blind, Placebo Controlled Study of the Short Term Clinical Effects of Tolvaptan in Patients Hospitalized for Worsening Heart Failure With Challenging Volume Management

The purpose of this study is to evaluate the short term efficacy and safety of tolvaptan in subjects hospitalized for worsening heart failure who have volume overload and one of the following: renal insufficiency, or hyponatremia or inadequate response to diuretic therapy. The primary variable for assessing efficacy will be self-assessed 7-point dyspnea score at 8 and 16 hours.