Within each section, we discuss how each specific approach can be used to assess alterations in cardiac structure and function under different conditions, including studies of aging, cardiomyopathies such as postchemotherapy, diabetes, or sepsis, myocardial infarction (MI), and pressure overload cardiac hypertrophy induced by transverse aortic constriction (TAC), angiotensin II infusion, or isoproterenol infusion. The gene discussed is AGT; the disease is myocardial infarction.