There are thousands of bridges in the world, but when it comes to "myocardial bridge", some people may not have heard of it, and today experts from Hunan Provincial Hospital of Traditional Chinese Medicine will unveil its mystery for you.
1. What is myocardial bridge?
Myocardial bridge is not a true bridge, but a congenital abnormal development of the coronary arteries. It refers to a coronary artery that is supposed to run in the epicardium through the muscle layer of the heart and travel in the heart muscle, this coronary artery is called the wall coronary artery or tunnel coronary artery, and the myocardial muscle covering it is called myocardialbridge (MB). When the heart contracts, the myocardial bridge compresses the walled coronary arteries, causing coronary artery stenosis.
2. Hazards and symptoms of myocardial bridges.
According to the depth of the parietal coronary artery, myocardial bridges are divided into superficial and deep types.
Superficial myocardial bridge because the covered myocardium is thin and short, the compression of the coronary artery is relatively light, generally does not cause severe myocardial ischemia, most of them are benign lesions, patients can have no symptoms, only occasionally appear transient chest tightness discomfort, can be relieved by itself;
The deep myocardial bridge is thick and long, the deeper the wall coronary artery travels, the more branches are involved, and the heavier the squeeze of the coronary artery during myocardial contraction, the greater the impact on blood flow, and the more likely the patient is to develop clinical symptoms. In particular, in the deep anterior descending artery myocardial bridge, patients can have obvious myocardial ischemia induced angina pectoris, and very rarely even acute myocardial infarction and sudden death.
3. Diagnosis of myocardial bridge.
At present, the main methods for diagnosing myocardial bridge include: coronary CTA and coronary angiography (DSA).
1. Coronary CTA:
In recent years, with the continuous development of multi-slice spiral CT technology, multi-slice spiral CT has enabled the diagnosis of myocardial bridge to get rid of the indirect judgment made by coronary angiography relying on the compression of the lumen, and rely on the objective display of the interrelationship between the concentric muscles of the wall coronary artery itself. Our hospital has the world's leading Siemens Force dual-source CT, which has many advantages such as fast scanning speed, low radiation dose, and excellent image quality, which can accurately diagnose myocardial bridges.
2. Coronary angiography:
Coronary angiography was the earliest diagnostic diagnosis of myocardial bridge, and the diagnostic criteria were the discovery of the typical systolic transient stenosis of the coronary artery at at least one projection position (which can be linear, beaded, or unclear or interrupted), and the diastolic lesion blood vessels completely or partially returned to normal, the so-called "** effect".
Coronary angiography (DSA) shows myocardial bridges.
According to the degree of systolic coronary artery stenosis, scholars such as Noble et al. divided myocardial bridging into **: first-class coronary artery systolic stenosis 50%; second-degree coronary systolic stenosis 50% to 70%; *Coronary artery systolic stenosis is 70%, and it is believed that patients with grade 2 or above are prone to myocardial ischemia and corresponding clinical symptoms.
Hunan Medical Chat Special Author: Chen Yong, Medical Imaging Department, Hunan Provincial Hospital of Traditional Chinese Medicine, Follow @Hunan Medical Chat to get more health science information!
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