Echocardiography, also called echo or cardiac ultrasound, is one of the most useful noninvasive tests to look at the heart. It offers valuable insight into heart structure and function and can be used to assess for any valve abnormalities, cardiomyopathies, or fluid buildup around the heart. There are different modalities of echocardiography, including transesophageal echocardiogram, which can be useful to look for any blood clots within the heart, particularly in patients with atrial fibrillation. Echocardiograms can also be used during other diagnostic tests, like stress tests or catheter procedures, to look for conditions like coronary artery disease or heart wall defects.