General preexcitation syndrome can be clarified by ECG, but there may be some atypical preexcitation syndrome or intermittent preexcitation syndrome which may not be captured or detected by normal ECG, in which case cardiac electrophysiology and 24-hour ambulatory electrocardiogram can be further improved to further clarify the diagnosis. Most pre-excitation syndromes are the result of congenital developmental abnormalities of the heart, which are abnormal pathways between the atria and ventricles in addition to the normal conduction pathways, which in turn lead to abnormal cardiac conduction. Most of the preexcitation syndromes can be identified by ECG. There may be a few preexcitation syndromes that are not obvious on ECG or are not captured because of the intermittent intervals, and then cardiac electrophysiology and 24-hour ambulatory electrocardiography can be chosen as further options to identify preexcitation syndromes compared to regular ECG. Generally, preexcitation syndrome may not have obvious symptoms, and most patients are found during physical examination. If the examination diagnoses preexcitation syndrome or there are symptoms such as discomfort in the precordial region, it is recommended to consult the doctor in time in order to avoid delaying the condition.