The electrocardiogram is the most commonly used clinical test and is included in all medical examinations. It records the normal electrical activity of the heart and helps doctors diagnose arrhythmias, myocardial infarction, heart enlargement, and the effects of drugs or electrolyte conditions on the heart. Although ECG is very common, there are some precautions that not everyone knows. There are 4 things to be aware of when having an ECG test. What are the precautions for ECG examination? 1, in order to ensure the accuracy of the ECG test, it is best not to fast before the test, because this may cause hypoglycemia, resulting in an accelerated heartbeat, thus affecting the accuracy of the ECG test results. 2, when doing ECG, especially 24-hour dynamic ECG, it is better not to wear chemical fiber clothes, because such clothing is easy to generate static electricity, thus affecting the results of the examination. Although the general hospital electrocardiogram machine is now able to anti-static interference, but there are many primary hospital electrocardiogram machine is not this function, so it is recommended to wear cotton clothes to do electrocardiogram. 3, when doing ECG, it is best to wear some clothes that are easy to put on and take off, especially in winter. Do not wear a jumpsuit or dress, because when doing an ECG you need to mention the clothes above the chest. If it is a jumpsuit or dress, when examining, you have to be almost completely naked, which will make both the doctor and the medical examiner feel embarrassed. 4, do not go to do ECG in a hurry, it is best to rest for a while before the examination, and then do the examination when you are calm. Rest for ten minutes first, meanwhile, do not smoke, drink alcohol as well as strong tea and coffee to avoid causing tachycardia or arrhythmia. Finally, it is important to maintain emotional stability during the EKG. Some women are afraid that they will be electrocuted, and their heartbeat will be accelerated before the ECG machine is turned on. In fact, these wires are only the heart’s bioelectricity “lead out”, will not input anything to the body, just like taking pictures of the human body is only the image of the actual record, so do not have a sense of fear, in order to make the test more accurate.