Under normal circumstances, the coronary arteries and their branches are shaped on the surface of the myocardium. When a segment of the coronary artery is shaped inside the myocardium, it is called a coronary artery myocardial bridge, also known as a myocardial bridge. A myocardial bridge is a congenital vascular malformation that can cause myocardial ischemia and even myocardial infarction. So, what are the clinical manifestations of myocardial bridges and how are they diagnosed and treated? Clinical manifestations and typing When the heart contracts, the myocardial bridge will squeeze the encapsulated wall coronary artery, resulting in obstruction of blood flow, causing insufficient blood supply to the myocardium. Clinical manifestations include palpitations, chest tightness, chest pain, and difficulty in inspiration and sweating during labor. The clinical manifestations of myocardial bridges are closely related to their staging. In superficial type, the myocardial bridge is thin and short, with little influence of coronary blood flow, and there are no symptoms of myocardial ischemia and related ECG changes; in deep type, the myocardial bridge is thick and long, with great influence of coronary blood flow, and angina pectoris and ischemic ST-T changes in ECG may appear. If myocardial bridges are complicated by rapid arrhythmias, myocardial ischemia is more likely to occur, and if coronary artery disease is encountered, it is undoubtedly an additional blockage in the narrow, and the ischemia is even worse. Myocardial bridges often develop after the age of 30 or 40, and the symptoms of chest tightness and chest pain are more obvious when the myocardial oxygen consumption is increased by exercise and exertion, emotional excitement and accelerated heartbeat. A part of young and middle-aged patients with atypical chest pain, if no obvious risk factors for coronary heart disease can be found, myocardial bridges should be suspected and the following tests can be done to clarify the diagnosis. 1.Coronary angiography If coronary artery systolic stenosis or combined with delayed diastolic relaxation is found, it indicates the presence of myocardial bridge. Coronary angiography can only detect myocardial bridges that have a significant effect on coronary blood flow. 2, intracoronary Doppler examination can detect myocardial bridge part of the coronary blood flow velocity in early diastole is significantly increased in a peak, and then quickly decreased, followed by a plateau until systole again decreased. The peak is due to the presence of a maximum intracoronary perfusion pressure and a corresponding continuous decrease in vessel area resulting in a significant pressure step difference between the two ends of the myocardial bridge. When the diastolic phase of the myocardial bridge relaxes, the pressure step difference between the two ends disappears and the vessel area rapidly expands and the flow velocity quickly decreases. Intravascular ultrasound reveals atherosclerosis in the coronary arteries proximal to the myocardial bridge, and intracoronary Doppler detects reduced intracoronary flow reserve. Treatment of myocardial bridges Myocardial bridges generally have a good prognosis, and about 12% of those without combined coronary atherosclerosis have angina symptoms, which occasionally cause acute myocardial infarction. However, some patients with myocardial bridges may experience post-exercise ventricular tachycardia or sudden death, so the treatment of myocardial bridges should be treated differently according to the specific conditions of the patients. 1.Medication β-blockers can reduce blood circulation and intracoronary pressure, reduce the degree of vascular compression, prolong the diastolic interval of the heart and improve coronary perfusion. Angina caused by systolic wall coronary artery compression may be effective for beta-blockers and calcium antagonists, such as verapamil and diltiazem. 2.Intracoronary stenting Intracoronary stenting can relieve angina symptoms in patients with persistent, severe angina and poor efficacy of β-blockers in myocardial bridges, and can be an important tool in treatment. After stenting, hemodynamic measurements, angiography, and intravascular ultrasound confirm that blood flow velocity, lumen diameter, and intracoronary pressure can be restored to normal. Stents with high flexibility and support are often chosen to achieve satisfactory stent expansion. 3.Coronary artery bypass grafting Coronary artery bypass grafting can be considered when the patient with myocardial bridge has obvious symptoms and there is a more extensive atherosclerotic plaque formation in the myocardial bridge. 4.myocardial bridge resection or coronary artery release Myocardial bridge resection or coronary artery release is feasible for patients with severe symptoms. It is mostly believed that surgical treatment is effective for patients whose ischemic symptoms persist even though they are treated with drugs. After surgery, the patient’s symptoms disappear, myocardial ischemia is relieved, and the electrocardiogram returns to normal, and no recurrence is observed for many years. However, the procedure is considered to be quite risky, mainly because the coronary myocardial bridging course is unpredictable and sometimes requires deep incision of the ventricular wall, which can potentially lead to subsequent abnormalities in ventricular wall structure and activity. Active control of risk factors Because myocardial bridges are a relatively common congenital anatomic malformation, there are no effective preventive measures. Attention should be paid to the prevention of various risk factors for coronary heart disease to prevent atherosclerosis of the coronary arteries and further aggravation of the disease. 1. Quit smoking and alcohol, consume low-calorie, low-fat, low-cholesterol, low-salt, high-fiber diet; keep bowel movements smooth; control weight in obese people; adjust daily life and workload, participate in physical labor and physical exercise appropriately, combine work and rest; ensure sufficient sleep; learn self-psychological regulation, keep a relaxed mood and emotional stability. Emphasize the importance of implementing a healthy lifestyle, and tell them to follow up and observe regularly after discharge, and instruct them to consult the doctor as soon as symptoms such as chest tightness, chest pain and weakness appear. 2. For patients with clinical symptoms, instruct them to stop activities and rest in bed immediately when symptoms occur; comfort patients and relieve tension and anxiety to reduce myocardial oxygen consumption; give oxygen inhalation; closely observe changes in heart rate, heart rhythm, blood pressure, as well as chest tightness and chest pain; actively give β-blockers, calcium antagonists, anti-platelet agents and anti-arrhythmic drugs as prescribed by the doctor; instruct patients to After discharge from the hospital, the patient should adhere to the medication, maintain a good lifestyle, and review regularly to prevent the occurrence of myocardial infarction and sudden death.