A blood test that would aid in the diagnosis and management of patients with congestive heart failure would have a favorable impact on the staggering costs of the disease. B-type naturetic peptide (BNP) is synthesized in the cardiac ventricles and its release is directly proportional to ventricular volume expansion and pressure overload. Levels of BNP correlate with left ventricular pressure, amount of dyspnea, and the state of neurohumoral modulation. BNP also correlates closely with New York Heart Association classification. A cut point of 100 pg/mL appears to discriminate patients with congestive heart failure from those without congestive heart failure. Measurement of BNP may also be an excellent screening tool for LV dysfunction. Key Words: Natriuretic peptides; neurohormonal; left-ventricular pressure;