An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves. These sound waves are converted into moving pictures of the heart. Echocardiograms are used to assess for structural abnormalities of the heart. Examples include ruling out weak heart pump function, disease of the heart valves, or congenital heart disease. This test is frequently used for patients with shortness of breath, fatigue, leg swelling better known as edema, or chest pain.