Research status of myocardial bridge

Myocardial bridge is the most common congenital coronary artery anomaly, the morbidity of autopsy was 42%, more in female patients(74.5%), mainly involves the left anterior descending branch(77.2%). The presence of myocardial bridge may be associated with various complications, such as angina pectoris, acute myocardial infarction, and even lead to severe clinical symptoms in early childhood. The possible damage mechanisms of myocardial bridge include myocardial ischemia, coronary spasm and coronary atherosclerosis. However, recent studies have considered the existence of the myocardial bridge may play a potential protective effect on the patients, and speculated that may be due to myocardial bridge near the adipose tissue and other connective tissue, form "coronary artery fat pad", helps blood vessels fight systolic bundle compression, myocardial bridge contraction stimulating anticoagulant and growth factor release, protection of mural coronary artery atherosclerosis. Myocardial bridge is caused by abnormal development of embryo, so it cannot be prevented in clinic. At present, there are mainly drug,surgery or interventional therapy. Interventional therapy is controversial, and surgical treatment is recommended, but there is no unified standard. For patients with depth>2 mm, length>25 mm and myocardial bridge compression persisting until diastolic phase cannot fully recover, coronary artery bypass surgery is recommended. In rare cases, emergency treatment may be needed, and even surgical intervention in early childhood is needed. This article reviews the research status of physiology, pathology, examination methods and treatment of myocardial bridge.