The investigators will enroll 30 patients who are in the cardiac intensive care unit with severe heart failure. The data collected will include weights, vital signs, laboratory results, and echocardiography results. A research lab test called B-type natriuretic peptide (BNP) will be done several times during this study. If the patient still has an intravenous (IV) catheter, the blood sample will be taken from the IV. If the patient does not have an IV, the sample will be taken from a fingerstick.