No, different sections of the cells' DNA are "tuned on" causing heart cells to have different characteristics from brain cells.
Heart cells (cardiomyocytes) and brain cells (neurons and glial cells) are distinct types of cells with different functions, structures, and roles in the body. While they originate from the same fertilized egg and have the same DNA, the differentiation process leads to the activation of different genes, resulting in diverse characteristics and functions.