Acute heart failure (AHF) is defined as a gradual or rapid change in heart failure (HF) signs and symptoms, such as shortness of breath (also called dyspnea or breathlessness), leg swelling, fatigue, breathlessness with exertion, trouble sleeping flat at night, and weight gain resulting in a need for urgent therapy. AHF results in over 1 million hospitalizations every year, resulting in an enormous public health burden. Approximately 1/3rd of patients will either be re-hospitalized or die within three months, and the resultant financial costs are large. As such, improving outcomes for AHF patients is critically important. Shortness of breath is the most common reason why patients with AHF present to the ER. As such, understanding how severe this symptom is, how much it improves with current treatments is very important to both patients and physicians. The purpose of this study is to determine the degree to which your shortness of breath improves during the first few days of hospitalization and its association with how fast you are breathing.