Atrial natriuretic peptide (ANP), a 28 amino acids polypeptide, is mainly secreted from the atrium of the heart where it is stored in secretory granules as a 136 amino acids pro-hormone (1). Upon its secretion, induced by increases in atrial pressure and stretch, the pro-hormone is processed by a serine protease to the active 28 amino acids peptide. The peptide binds with high affinity to the membrane receptor guanylate cyclase GC-A, leading to increased intracellular cGMP levels (2). Increased ANP plasma level has been identified as predictors of cardiac dysfunction and prognosis in congestive heart failure and ischemic heart disease (3-5). Lower plasma levels of ANP will lead to sodium retention, and an increase in plasma volume, resulting in an increase blood pressure (6).