A narrowing of the lumen of the myocardial bridge in the middle of the anterior descending branch of the left coronary artery affects myocardial blood supply. Myocardial bridge is a kind of developmental malformation of the heart, part of the coronary artery is covered by myocardium, myocardial contraction process will cause compression of the coronary artery, resulting in patients with varying degrees of insufficient blood supply to the myocardium, the faster the number of heartbeats, the more obvious symptoms of myocardial ischemia. Myocardial bridges are likely to occur in the anterior descending branch, mainly affecting the supply and demand of the anterior wall, patients with myocardial bridges should pay attention to appropriate control of the heart rate, such as the heart rate is too fast, you can follow the doctor’s instructions to give metoprolol treatment, control the heart rate, reduce the number of times the coronary arteries are compressed, can be appropriate to alleviate the symptoms, the symptoms of the particularly pronounced effect of drug therapy is not good, feasible coronary bypass grafting treatment. Metoprolol is a beta-blocker, has the effect of slowing down the heart rate, the adverse effects of the drug are dizziness, hypotension, bradycardia, cold extremities, nausea, etc. Allergy to the drug components, severe bradycardia, cardiogenic shock, bronchial asthma, the second degree of three degrees of atrioventricular block is prohibited in patients. Patients with myocardial bridges should assess the severity of their condition under the guidance of a physician, and treatment should be given appropriately if the symptoms are obvious.