Cardiac endocrine function is an essential component of the homeostatic regulation network: physiological and clinical implications

The discovery of cardiac natriuretic hormones required a profound revision of the concept of heart function. The heart should no longer be considered only as a pump, but rather as a multi-functional and interactive organ, part of a complex network and active component of the integrated systems of the body. In the present review, we will first consider the cross-talk between endocrine and contractile function of the heart. Then, based on the existing literature, we will propose the hypothesis that cardiac endocrine function is an essential component of the integrated systems of the body and thus plays a pivotal role in fluid, electrolyte and hemodynamic homeostasis. We will highlight those studies indicating how alterations in cardiac endocrine function can better explain the pathophysiology of cardiovascular diseases and in particular of heart failure, in which several target organs develop a resistance to the biological action of cardiac natriuretic peptides. Finally, we will emphasize the concept that a complete knowledge of the cardiac endocrine function and of its relation with other neurohormonal regulatory systems of the body is crucial to correctly interpret changes in circulating natriuretic hormones, especially the brain natriuretic peptide.