Myocardial Bridge as a Structure of “Double-Edged Sword” for the Coronary Artery

Abstract

Myocardial bridge (MB) is a chance anatomical structure, comprised of the myocardial tissue, with which the coronary artery running in epicardial adipose tissue is partly covered. It is predominantly present in the left anterior descending artery (LAD) and recognizable through imaging techniques as changes in blood fl ow within the LAD that arises from MB contraction at cardiac systole. Such changes in blood fl ow infl uence the pathophysiology of coronary circulation and atherosclerosis development, thus generating controversy as to whether MB predisposes individual to myocardial infarction (MI). However, recent histomorphometric studies have shown that the individual anatomic properties of MB, such as location, length and thickness, consistently play a critical role in the occurrence of MI. This review article comprehensively addresses the pathophysiological mechanisms of MI occurrence together with the benign suppressive effect of coronary atherosclerosis by MB.

Assessment of cardiac autonomic functions by heart rate recovery indices in patients with myocardial bridge

“…Myocardial bridging is defined as a segment of a major coronary artery course through the myocardium that normally has an epicardial course [15,16]. In the last decade, it was shown that myocardial bridging can be very well depicted by CCTA which has increased the interest in this anomaly [3,17].…”

Coronary artery perforation in a patient with STEMI and a myocardial bridge: an increased risk for coronary artery perforation?

“…The vessel is running intramurally and thus is being bridged by muscle fibers. Myocardial bridging predominantly involves the LAD [1]. A superficial and a deep type of MB may be distinguished.…”

“…High shear stress leads to alignment of endothelial cells in the direction of blood flow, therefore being more resilient to the diffusion of pro-atherogenic factors. Atherosclerosis is induced in the segments proximal to an MB however, caused by turbulent and complex blood flow due to systolic flow reversal and increased intra luminal pressure in the proximal segment [1].…”

Myocardial Bridges on Coronary Computed Tomography Angiography ― Correlation With Intravascular Ultrasound and Fractional Flow Reserve ―

“…We calculated the MMI as MB length (mm)×MB coverage; 1, 2 or 3. 3 The presence or absence of atherosclerotic plaque proximal to the MB was assessed. When present, plaques were categorized into 5 groups (no plaque, non-calcified, mixed, calcified, and stented).…”