Myocardial bridge is a congenital vascular malformation. Cardiac contractility during coronary artery myocardial bridge cover are oppressed, there systolic stenosis, diastolic coronary oppression has been lifted, coronary artery stenosis have been relieved. 1960 postsmann and wig will first describe the muscle bridge in vivo angiography, mainly through angiography, see "systolic narrowing or milking effect" to identify its clinical significance has been debated.
Coronary artery and its branches are usually walking on the surface of the heart, epicardial fat or the epicardial deep surface, when the period of myocardial coronary artery was surrounded, the myocardium is known as a myocardial bridge, the segment of coronary artery known as the wall of coronaryartery. Myocardial bridge may be related to local factors and coronary heart disease may also cause myocardial ischemia.
1, the rate of myocardial bridge: Due to the different research methods, detection varies widely. Pathological series, its incidence vary widely, from 15% to 85%, while in the angiography series, the incidence rate of 051% to 25%. The Yetman such as that caused Both a large rate difference depends on several aspects: the length of the myocardial bridge, the accurate positioning of the left anterior descending artery bridge fiber, the relationship between myocardial bridge and the adjacent artery, the angiographic myocardial bridge not commensurate with the rate dependent on the length of the myocardial bridge, angiography is only aware of the deep muscle bridges, shallow muscle bridge when angiography is not easy to find. Report the application of nitroglycerin to increase the left anterior descending artery myocardial bridge systolic stenosis detection, thereby increasing the detection rate of myocardial bridge. Myocardial bridge detection rate in patients with hypertrophic cardiomyopathy patients, 30% to 50%, 28% of the incidence of children with hypertrophic cardiomyopathy, myocardial bridge. 7467 consecutive coronary angiography Juilliere and other reports, however, found that the myocardial bridge in 61 cases, 26 cases of coronary heart disease, four cases of heart valve disease, three cases of hypertrophic cardiomyopathy, and the remaining isolated myocardial bridge. Detected in patients with myocardial bridge, myocardial disease is not dominant.
Myocardial bridge with age, gender relations: myocardial bridge after birth, existence, development and adjacent arterial growth is closely related. Myocardial bridge in the rate of male slightly more than women, but there are also the authors suggest that no significant gender differences. Ferreira et al. Report for 90 cardiac autopsy findings, 50 heart myocardial bridge, including 32 males, 18 females, whose ages range from stillborn to 84 years, previously had no history of heart disease patients died of noncardiac disease caused by3, the location and number of myocardial bridge: myocardial bridge occurs most frequently in the left anterior descending artery, and located near the vessel, in 1/3, myocardial bridges can be a single can also be more occurrences of more occurrences of muscle bridge in the same vascular or coronary artery or their branches. Ferreira et al reported 50 myocardial bridge autopsy, 35 single muscle of the heart of the Department of the bridge, involving the left anterior descending artery, 10 the two muscles of the heart of the Department of bridge, heart, Department 3 5 muscle bridge. Juilliere such as detection of myocardial bridge in 7467 cases of coronary angiography, 61 cases are located in the left anterior descending artery. Also reported in the literature angiography cases of myocardial bridge in the right coronary artery.
Myocardial bridge - the cause of
Myocardial bridge is a relatively common congenital anatomic deformity. Cause of coronary artery myocardial segment, particularly within the segment of the left anterior descending artery myocardial systolic can be squeezed, and more symptoms of myocardial ischemia in middle age.
Myocardial bridge - pathogenesis
Myocardial bridge, myocardial bridge, myocardial fiber direction of the front descending artery and posterior descending artery at the vascular long axis nearly right angle before the right ventricular branch and left ventricular branch was at a slight angle.
Cross-section of the wall of coronary artery visible lumen is small, thin wall becomes more apparent when the myocardial bridge, thick wall of the coronary segments difficult to form atherosclerosis while its proximal and distal intimal you can often see atherosclerosis sclerosis.
Because of these anatomical features, when the contraction of the heart, myocardial bridge oppression mural coronary artery to lumen further narrow myocardial bridge the longer the thick myocardial fibers and blood vessels into the angle the greater the wall of coronary artery stenosis and the heavier the distal myocardial ischemia The more weight, or myocardial infarction.
Myocardial bridge - the pathophysiology of
Myocardial bridge, myocardial fiber direction of the front descending artery and posterior descending artery at the vascular long axis of the nearly right angle, before the right ventricular branch and left ventricular branch was at a slight angle. Cross-section of the wall of the coronary arteries visible lumen small, thin wall becomes more apparent when the thick of the myocardial bridge. The wall of the coronary segments difficult to form atherosclerosis, proximal and distal intimal atherosclerosis can frequently be seen. Because of these anatomical features, when the contraction of the heart, myocardial bridge oppression mural coronary artery, so that further narrow the lumen, and myocardial bridge is the longer, thicker, cardiac muscle fibers and blood vessels into the angle the greater the wall the more severe coronary artery stenosis, remote the more severe myocardial ischemia or myocardial infarction.
