Heart Failure remains a common presentation in the emergency department. For the emergency physician clarifying the course of the universal complaint, shortness of breath, requires excellent clinical acumen combined with a clear understanding of the laboratory tests available to distinguish Heart Failure from other causes of dyspnea. Dr. Frank Peacock of the Cleveland Clinic authors an excellent discussion of the scientific basis for the use of the natriuretic peptide biomarkers in heart failure including future markers currently being investigated.