Inclusion Criteria:

• * Age \> 18
• * Emergency Department diagnosis of Acute Heart Failure (AHF)
• * Any one of the following:
• i. Chest radiograph or lung ultrasound consistent with AHF ii. Jugular venous distension iii. Pulmonary rales on auscultation iv. Lower extremity edema v. S3 gallop
• * \> 10 pounds of volume overload physician estimate or historical dry weight
• * IV diuretic ordered or planned to be during first 24 hours of ED or inpatient stay

Exclusion Criteria:

• * End Stage Renal Disease (ESRD) requiring dialysis
• * Need for immediate intubation
• * Acute Coronary Syndrome - presentation consistent with myocardial ischemia AND new ST-Segment elevation/depression
• * Temperature \> 100.5ºF
• * End Stage Heart Failure: transplant list or ventricular assist device
• * Concurrent use of ototoxic medications including intravenous aminoglycosides and cisplatin
• * Systolic Blood Pressure \< 90 mmHg at time of consent
• * LV outflow obstruction, severe uncorrected stenotic valvular disease or severe restrictive cardiomyopathy
• * Greater than 2 doses of IV diuretic administered at the time of screening from the time of the hospital presentation leading to this admission (outside hospital time is included)
• * Severe, uncorrected serum electrolyte abnormalities at the time of consent (serum potassium \<3.0 mEq/L, magnesium \<1.0 mEq/L or sodium \<125 or \>150 mEq/l)
• * Lack of informed consent