Echocardiography (EK-o-kar-de-OG-rah-fee), or echo, is a painless test that uses sound waves to create moving pictures of your heart. The pictures show the size and shape of your heart. They also show how well your heart's chambers and valves are working.
Echo also can pinpoint areas of heart muscle that aren't contracting well because of poor blood flow or injury from a previous heart attack. A type of echo called Doppler ultrasound shows how well blood flows through your heart's chambers and valves.
Echo can detect possible blood clots inside the heart, fluid buildup in the pericardium (the sac around the heart), and problems with the aorta. The aorta is the main artery that carries oxygen-rich blood from your heart to your body.
Doctors also use echo to detect heart problems in infants and children.