Heart failure etiology and response to milrinone in decompensated heart failure: results from the OPTIME-CHF study. - Felker,G.M.; Benza,R.L.; Chandler,A.B.; Leimberger,J.D.; Cuffe,M.S.; Califf,R.M.; Gheorghiade,M.; O'Connor,C.M. (J Am Coll Cardiol, 2003)