AGT and familial cardiomyopathy: We took into consideration the following: 1—Ang II induces cardiac hypertrophy associated with an increase in cardiomyocyte intracellular Ca2+ and ROS [15]; 2—the first abnormal remodeling takes place at the EE during the development of hereditary cardiomyopathy, and it contributes to cardiovascular dysfunction [21]; 3—endothelial cell dysfunction is a complex mechanism [29] implicating ROS generation and overload that is also activated by Ang II [22,23,24,25].