Even though the names sound similar, both electrocardiography and echocardiography are different. While electrocardiography records the electrical activity of the heart, echocardiography uses sound waves to create a moving image of an unborn’s heart. Doctors use electrocardiography to diagnose heart conditions like arrhythmias or heart attacks. On the other hand, echocardiography is used to see the heart’s structure and functioning. It also detects any abnormalities like congenital heart diseases, blood flow, or heart rhythm abnormalities.