To create an image of the heart, a echocardiograph technician uses a transducer that looks like a short, fat wand. You will lie mostly on one side and be asked to follow the technicians instructions to breath in and out or to hold your breath as the wand is pressed against your chest. Ultrasound waves travel through the chest and bounce off the chambers, valves and major vessels of the heart. The "echoes" of the sound off the surfaces of the heart are converted into an image that can then be displayed on a monitor.
Two variations of echocardiography are Doppler ultrasound and exercise echocardiography.
An exercise echocardiogram is done while you exercise. This can provide a better idea of the coronary artery blood flow than an echocardiogram done during rest. If you are unable to exercise, a drug can be used to increase blood flow, mimicking what happens during exercise.