A specially trained technician performs this test. It is a test that uses high frequency sound waves to generate pictures of your heart.  During the test, you generally lie on your back and gel is applied to your skin to increase the conductivity of the ultrasound waves. The technician then moves the small, plastic transducer over your chest. The test is painless and can take from 10 minutes to an hour.

The machine then analyses the information and develops images of your heart. These images are seen on a monitor. This is referred to as an echocardiogram.

Echocardiography can help in the diagnosis of many heart problems including cardiovascular disease, previous heart attacks, valve disorders, weakened heart muscle, and holes between heart chambers.

If doctors are looking for evidence of coronary artery disease they may perform variations of this test which include

Exercise echocardiography. This technique is used to view how your heart works under stress. It compares how your heart works when stressed by exercise versus when it is at rest. The ultrasound is conducted before you exercise and immediately after you stop. Either a stationary bicycle or standard treadmill is used. 

Dobutamine stress echocardiography. If you're unable to exercise for the previous test, you might be given medication to simulate the effects of exercise. During this test, an echocardiogram is performed when you're at rest. Then medication dobutamine is then given to you via a needle into a vein in your arm.  Its effect is to make your heart work harder and faster just like with exercise.  After it has taken effect, the echocardiogram is repeated and compared.   The effects wears off very quickly.