Echocardiogram uses sound waves to create pictures of the heart. The test is done when pericardial effusion (build-up fluid around the heart) is suspected. It also assesses how well the heart functions. During the procedure the patient lies on a table and a gel is put on the skin over the chest. A technician places a transducer on the chest and upper abdomen. An echocardiography converts the impulse received from the transducer into moving or still pictures of the heart.