In daily life, the causes of tachycardia are mostly seen in healthy people when they drink alcohol, strong tea or coffee, smoke, run, do heavy physical work and get emotional. Other pathological conditions such as fever, anemia, hyperthyroidism, bleeding, pain, hypoxia, heart failure, and myocardial ischemia can also cause tachycardia. We must first know what is tachycardia. I. What is tachycardia? In a person with normal sinus rhythm, the impulse originates from the sinus node at a frequency of 60-100 beats/min, and a frequency of more than 100 beats/min is called tachycardia. B. What are the common types of tachycardia? 1, sinus tachycardia: characterized by a gradual change in heart rate acceleration; the frequency is mostly between 100-150 beats per minute, occasionally up to 200 beats per minute; stimulation of the vagus nerve can cause its frequency to gradually slow down, and then accelerate to the original level after stopping stimulation. 2, paroxysmal supraventricular tachycardia: the heart rate can reach 150-200 beats per minute, characterized by sudden onset and sudden stop, without organic heart disease, different sexes and ages can occur. During the attack, the patient suddenly feels palpitations, chest tightness, dizziness, discomfort in the precordial region and tension in the head and neck, anxiety, and rarely syncope and angina. The severity of symptoms depends on the degree and duration of rapid ventricular rate during the attack. 3. Ventricular tachycardia: It often occurs in patients with various organic heart diseases. The most common is coronary artery disease, especially in patients who have had a myocardial infarction. This is followed by cardiomyopathy, heart failure, mitral valve prolapse, heart valve disease, etc. Other etiologies include metabolic disorders, electrolyte disturbances, long QT syndrome, etc. Ventricular tachycardia can occasionally occur in people without organic heart disease. However, it should be noted that when the tachycardia attack is long and the heart rate is above 200 beats per minute, the patient may experience blackness, dizziness, weakness and nausea and vomiting, or even sudden fainting and shock due to hemodynamic changes. Tachycardia in patients with coronary artery disease often induces angina pectoris. Third, if a patient develops tachycardia with normal cardiac function and blood pressure, what should be done for first aid? Try the following simple methods to stimulate the sympathetic and vagus nerves to regulate the heart rate: 1. Have the patient cough hard to make the chest and abdominal muscles work together; 2. Compress one side first, then change to the opposite side if it is not effective. Do not press both sides at the same time and use too much force. Tachycardia should be stopped immediately. Glaucoma and highly myopic eyes are contraindicated. If the tachycardia cannot be effectively relieved for a short period of time by the above methods, the patient should be sent to hospital immediately for treatment. At present, cardiac electrophysiological examination, radiofrequency ablation treatment technology has been very mature, safe, effective, and can cure all types of tachycardia, tachycardia frequent patients should be given priority to apply.