The purpose of this study is to test the use of tolvaptan (commercial name Samsca) when given
in addition to intravenous (IV) diuretics early during an episode of acute heart failure. It
will be compared to a high dose of IV diuretics alone or the use of metolazone in addition to
IV diuretics. The investigators are looking to see if there is improvement in the symptoms
and outcomes of persons with acute heart failure.