This project is anchored at the interface between two areas of knowledge: Physiology and Immunology. Although the presence of macrophages resident in various tissues of the body is not new (such as microglia in the brain, Kupffer cells in the liver, etc.), it was only with the emergence of more sophisticated techniques in the last decade that it was possible to identify and characterize macrophages resident in the heart. These cells are involved in several important biological functions, such as blood vessel formation and electrical conduction. In this project, we intend to investigate the existence of cellular communication between resident macrophages and the heart muscle cell, the cardiomyocyte. We hypothesize that macrophages present in cardiac tissue can detect physiological changes and contribute to a homeostatic response that will help the heart adapt to a stressful stimulus.