Most of the inpatients who are scheduled for cardiac ultrasound see the ultrasound instrument and think they are looking at the abdomen, not knowing that they can have their heart examined with ultrasound. There are also some patients who cannot tell the difference between ECG and cardiac ultrasound and often complain that they have an ECG and why they have an ultrasound. This is a lack of understanding of cardiac ultrasound, not knowing what this test is testing for and what it means. The most prominent feature of cardiac ultrasound is that through flexible manipulation, multi-directional and multi-angle real-time dynamic scanning, observation of cardiac structure, evaluation of ventricular wall motion, opening and closing of valves, and determination of cardiac function. It is mainly used for the diagnosis of various heart diseases, treatment detection and evaluation of cardiac function before and after surgery. Transthoracic cardiac ultrasound can be divided into M ultrasound, Doppler ultrasound, two-dimensional ultrasound, three-dimensional ultrasound, etc. This method is safe, non-radioactive, has high diagnostic accuracy, no pain or damage to the patient, is relatively inexpensive, has rapid and timely examination results, and can be repeatedly examined several times, and has become one of the most commonly used and important cardiac examination methods in clinical practice.