The document discusses three common cardiac diagnostic tests: cardiac enzyme tests, stress testing, and echocardiography. Cardiac enzyme tests measure levels of enzymes in the blood that can indicate a heart attack. Stress testing evaluates how well the heart handles increased activity levels to identify issues like coronary heart disease. Echocardiography uses ultrasound to examine the structure and function of the heart, detecting abnormalities and conditions of the valves and arteries. These tests help doctors identify potential heart problems, determine treatment plans, and establish safe exercise routines.