If the patient has chest pain, for patients with a previous history of significant coronary artery disease, there will be clinical symptoms of tachycardia, this is because severe chest pain will lead to an increase in sympathetic nerve tone, at this time, it will reflexively lead to a faster heartbeat, increased heart rate, enhanced myocardial contractility, increased conduction velocity of the heart, there will be an increase in the amount of postcardiac oxygen in the cardiac myocytes, and there will be a cardiac energy supply and oxygen demand Imbalance, the patient will further aggravate the ischemia, stenosis, spasm of coronary arteries, and there will also be the clinical symptoms of chest pain, so it will form a vicious circle. In addition, severe chest pain can also cause an increase in blood pressure, and when the blood pressure increases, there will also be activation of the renin-angiotensin-aldosterone system in the body, and in this case of neurohumoral-endocrine system disorders can also lead to tachycardia.