Premonitory syncope is a relatively common vascular syncope in young people, and is very common. It often recurs, especially when under considerable emotional stress, extreme fatigue, pain, panic, or in a crowded, hot room, and is more likely to attack. So, what are the tests that need to be done for syncope prognosis? The following is a list of tests for syncope: 1. Structural heart disease related 1. Cardiac ultrasound can identify organic heart disease (aortic stenosis, atrial mucinous tumor, pericardial compression, etc.). Esophageal ultrasound can be performed in some cases. 2. CT and MRI, CTA: CT and MRI are indicated for patients with specific diseases (aortic coarctation, pulmonary embolism, cardiac mass, pericardial and myocardial disease, congenital anomalies of the coronary arteries, etc.). Arrhythmia-related investigations 1. ECG monitoring: This includes ambulatory ECG (Holter), monitoring during hospitalization, implantable electrocardiographic recorders (ILR), and remote (home) monitoring systems. systems. Immediate in-hospital ECG monitoring for high-risk patients. Patients with frequent episodes of syncope or aura syncope should undergo Holter examination. 2. Intracardiac electrophysiological examination: The most common cause of cardiogenic syncope is cardiac arrhythmia, which can lead to significant reduction in cardiac output and cerebral blood flow due to hemodynamic changes, resulting in syncope. The types include: ① pathological sinus node syndrome (including slow fast syndrome). (ii) Atrioventricular conduction system disorders. (iii) Supraventricular tachyarrhythmias. ④Ventricular tachyarrhythmias. ⑤ Long QT syndrome. ⑥Brugada syndrome. (7) Pacemaker and ICD related. (viii) Arrhythmogenic effect of drugs. The gold standard for the diagnosis of arrhythmic syncope should be the occurrence of syncopal symptoms along with arrhythmias recorded on ECG monitoring. However, syncope occurs intermittently and the duration of symptoms is brief, and conventional tests such as ECG and Holter have a low diagnostic yield for arrhythmic syncope. Electrophysiological examination (EPS) identifies the possible causes of syncope by assessing sinus node function, atrioventricular conduction function, induced supraventricular arrhythmias and ventricular tachycardia, and makes a risk assessment for future events to guide treatment. When syncope is suspected to be caused by severe arrhythmias, and conventional ECG, Holter examination cannot reveal the above evidence, intracardiac electrophysiological examination can be performed.