Pre-excitation syndrome itself does not have any symptoms, only in the electrocardiogram shows a Δ wave, P-R interval shortening, ST-T abnormalities, but if this part of the population has a tachycardia, pre-excitation electrocardiogram manifestations coupled with tachycardia episodes is known as the pre-excitation syndrome; the specific content is as follows: 1, when this type of people have a tachycardia will be manifested as palpitations, if the heart rate is particularly fast, generally at least 160 beats / min or more, pre-excitation tachycardia episodes can jump to 200 beats / min or even 200 beats / min. Generally at least 160 beats/minute or more, when the tachycardia attack can jump to 200 beats/minute or even more than 200 beats/minute, this type of people in addition to panic may have chest tightness, dizziness; because the heartbeat is too fast on the cerebral blood supply is insufficient, manifested as panic, dizziness, chest tightness; and there is a part of the population heartbeat is particularly fast when the heartbeat can be manifested as a fainting spell; this is a patient with the syndrome of pre-excitation! This is the typical clinical manifestation of tachycardia in patients with preexcitation syndrome; 2, there is also a part of the population with preexcitation combined with atrial fibrillation, tachycardia attacks at the same time combined with another type of arrhythmia, for this type of population his risk is higher than the rest of the population, this part of the population may preexcitation combined with atrial fibrillation downward ventricular too fast, which will induce ventricular tachycardia, ventricular fibrillation or even lead to the death of the patient. So for this type of people, once you find preexcitation syndrome combined with tachycardia, and preexcitation combined with the occurrence of atrial fibrillation, you must be recommended to go to the hospital as soon as possible, is to avoid the occurrence of malignant events.