Electrocardiogram and ultrasound are not comparable, the contents of both tests are different, there is no such thing as “which is better”. 1. Electrocardiogram (ECG) is a commonly used means of examination in clinical work, which is mainly used to determine whether there is any abnormality in the rhythm of the heart, whether there is any arrhythmia, whether there is any myocardial ischemia or myocardial infarction, whether there is any enlargement of the heart, whether there is any effect of medication or electrolyte disorders on the heart, and whether there is any effect on the status of the artificial cardiac pacemaker. 2. Cardiac ultrasound is mainly used to determine the position of the heart and the relationship between the heart and internal organs; to check whether there is any abnormality in the structure of the heart; to evaluate the changes in the hemodynamics of the heart, to measure the flow rate and differential pressure of the valves, and to determine the location and origin of abnormal blood flow in the cardiovascular system; to detect pericardial diseases; to evaluate the recovery of the heart structure and the hemodynamic regression after cardiac surgery and interventional therapy. In conclusion, ECG and cardiac ultrasound have different and complementary uses and are not substitutes for each other.