1, single-lead ECG: is only one ECG pen tracing out the ECG, after making the ECG only very narrow a long strip, according to the sequence of recording Ⅰ, Ⅱ, Ⅲ, aVR, aVL, aVF, V1-V6 leads of the ECG, that is, Ⅱ leads of the graph after the Ⅰ leads, Ⅲ leads of the ECG after the Ⅱ leads, and so on (see the following figure, due to the limitation of space The ECG in lead Ⅰ and lead Ⅱ is shown in the figure below, and so on (due to space limitation, only leads Ⅰ and Ⅱ are shown). 2.Synchronous recording of ECG in multiple leads: Six pens or 12 pens are used to record ECG in 6 leads or 12 leads simultaneously. This kind of ECG is “stacked one on top of the other” from top to bottom, and the ECG patterns of each lead can appear at the same time, that is, synchronously. For this reason, it can assist in the diagnosis of some complex arrhythmias (the figure below shows that the sequence of the 6 leads from top to bottom I, II, III, aVR, aVL, and aVF on the left side appears to be synchronously tuned, and the V1-V6 leads from top to bottom on the right side are synchronously tuned). 3, 24-hour dynamic ECG (Holter): Most patients with arrhythmia, once in the hospital, do not commit, even if the ECG can not capture the arrhythmia ECG, for this reason set up this ECG recording device. Holter recorder is like a small semiconductor, through several leads with electrodes pasted to the chest leads connected to the recorder, so it can be 24 The ECG signal is recorded continuously for 24 hours. The next day, when the recorded ECG signal is replayed at the hospital, the doctor will know the type, duration and severity of the arrhythmia, and whether there is an episode of myocardial ischemia, etc. The record shows up. 4. High-frequency ECG: The tracing speed of the ECG machine is significantly accelerated, so the waveform is widened many times, so that the presence of some cut stutter in the graph can be carefully identified. Coronary artery disease and some myocardial damage can have too many traces or stutters. 5. Late ventricular potentials: For patients with coronary artery disease, myocardial infarction, and severe arrhythmias, this test can be performed to see if there is any dangerous information that will be present. It is a fragmented graphic recording of the high-frequency components of the later part of the end of certain waveforms (cardiac waveforms) through special computer technology. 6. Esophageal ECG: It can be done by inserting electrodes through the nasal cavity into the esophagus up to a specific part of the heart, which can record a clearer ECG graphic and assist in the diagnosis of some difficult arrhythmias. In addition, if there is a suspicion of severe damage to the sinus node, the commander-in-chief of the heart, resulting in “sick sinus syndrome”, pre-excitation syndrome, or certain less diagnostic tachycardias, the diagnosis can be confirmed by the pacing technique of the esophageal ECG. In addition, there are other electrocardiograms (e.g., intracavitary electrocardiograms) that are less commonly used and therefore will not be described here.