Whether a myocardial bridge in the middle of the left anterior descending branch is dangerous or not needs to be judged according to the depth of the myocardial bridge and the presence or absence of symptoms, etc. Superficial myocardial bridges are generally not at great risk, while longitudinal myocardial bridges with obvious symptoms are at greater risk. In myocardial bridge patients, the coronary arteries supplying blood to the myocardium have congenital developmental abnormality, and the coronary arteries originally located on the surface of the myocardium are partially covered by the myocardium. When the myocardial cells contract, the part of the coronary arteries covered by the coronary arteries will be squeezed, which affects the blood supply to the corresponding part of the myocardium. 1. Superficial myocardial bridge: If the myocardial bridge is superficial, the coronary artery is not covered too deeply, its blood flow is less affected by the contraction of the cardiomyocytes, and the patient can be symptomless, without ECG changes of myocardial ischemia, and is generally not at great risk. 2. Longitudinal myocardial bridge: If the myocardial bridge is of longitudinal type, the covered coronary artery may be squeezed more obviously, and may affect the blood supply of the corresponding cardiomyocytes, and the ischemia of myocardium may cause the body to experience chest pain, chest tightness, panic, fatigue and other discomforts, and in serious cases, it may lead to acute myocardial infarction, heart failure or even death, and therefore it may be more dangerous. If the results of left anterior descending middle myocardial bridge examination is abnormal, it is recommended to consult a doctor in time for a clear diagnosis and targeted treatment or therapy.