An echocardiogram (echo) is a type of ultrasound test that uses sound waves to create images of the heart. While an echo can provide information about the structure and function of the heart, it is not a reliable test for detecting blockages in the arteries that supply blood to the heart muscle. To diagnose blockages in the coronary arteries, other tests such as a coronary angiogram, CT angiogram, or stress test may be needed. These tests can provide detailed images of the heart and its blood vessels and can help identify blockages and other abnormalities that may be affecting the heart.