Patients who have had episodes of supraventricular tachycardia tend to have several major manifestations: 1. A rapid heartbeat. This means that the heart rate exceeds what is needed in the body’s physiological state. In general, the heart rate during episodes of supraventricular tachycardia is usually 150-200 beats/min, but it is not uncommon for some patients, especially when the conduction capacity of the other conduction pathway is poor, to have a heart rate of 120-130 beats/min during tachycardia. 2. Sudden onset and termination. Generally speaking, the onset of supraventricular tachycardia is sudden and abrupt, that is, it jumps from the normal 100 beats/min to the frequency of tachycardia, such as 150 beats/min, and this frequency does not change greatly. And the termination is also better all at once, which can drop from 150 beats/min directly to a normal heartbeat, such as 80 beats/min. Of course, some patients’ heartbeat may increase significantly to about 100 beats/min at the end of the attack due to nervousness and other discomfort, but it is not the same frequency as the heartbeat at the time of the attack. 3. The heartbeat is regular and uniform. Generally speaking, the heartbeat during an attack of supraventricular tachycardia is relatively regular and neat, and there is no feeling of stopping or going fast and then slow, which means that the supraventricular tachycardia either comes on or ends, and does not change between fast and slow heartbeat frequently. This can be confirmed by the patient’s own pulse measurement. 4, some patients may have chest tightness, dizziness and other uncomfortable performance during the attack.