Cardiac ultrasound is a very necessary test for patients with coronary artery disease, such as: 1. For patients with coronary artery disease, cardiac ultrasound can determine whether they have heart structures, such as defects, increase, thickening, stenosis, widening, fissure or a certain evaluation of the heart valve function. 2. 3.3 The cardiac ultrasound can also make differential diagnosis between coronary heart disease and other heart diseases, such as rheumatic heart disease, heart tumor, pericardial effusion, etc.