Echocardiogram (echo) is a test used to evaluate the function and structure of the heart. A Stress Echocardiogram is a test done to evaluate how well the heart works under pressure. The "stress" can be provoked either by treadmill exercise or by a medication called dobutamine. Dobutamine stress echocardiogram (DSE) could be used if you are not capable of exercising. Dobutamine is placed in a vein and induces the heart to beat faster. It imitates the effect of physical activity on the heart. 

During an echo, a transducer (like a microphone) sends ultrasonic sound waves at an intensity too high to be noticed. When the transducer is positioned on the chest at certain areas and edges, the ultrasonic sound waves move through the skin and other body tissues to the heart tissues where the currents bounce or "echo" from the framework of the heart. The transducer picks up the vibrations and sends them to the desktop. The computer exhibits the echoes as images of the walls and valves of the heart.