Recently, emergency physicians have been using portable ultrasound at the patient's bedside to diagnose numerous conditions, including trauma, blood clots, kidney stones, etc. Recent research suggests that heart failure, one of the causes of shortness of breath, may be diagnosed within 5 minutes or less using ultrasound. Most of these studies come from the intensive care and cardiology. However, no research has yet been performed to determine if emergency physicians can effectively use ultrasound to quickly diagnose and treat heart failure within the first few minutes of a patient's arrival to the emergency department. The hypothesis of this study is to evaluate the ability of residents in emergency medicine to use ultrasound to diagnose patients in heart failure who presented with the chief complaint of shortness of breath. The final diagnosis of the patient upon discharge from the hospital will be compared to the preliminary diagnosis based on the portable ultrasound findings.