The impact of myocardial bridge on coronary artery spasm and long-term clinical outcomes in patients without significant atherosclerotic stenosis

The Significance of Recognizing Myocardial Bridge in the Coronary Spasm Diagnosis in Myocardial Infarction with Nonobstructive Coronary Arteries

“…Several recent studies have focused on the correlation between the myocardial bridge and coronary spasm, demonstrating the presence of coronary spasm at segments with a myocardial bridge (5)(6)(7)(8)(9)(10)(11)(12)20). The precise mechanism underlying the correlation has not yet been established.…”

“…Of these, coronary spasm is considered to be one of the major causes of MINOCA (3,4); however, in some emergency cases, it is challenging to determine the correlation between the coronary spasm and MI-NOCA because of prior nitroglycerin (NTG) administration. Furthermore, a correlation between the coronary spasm and the myocardial bridge has been reported (5)(6)(7)(8)(9)(10)(11)(12).…”

Coronary spasm: It’s common, but it’s still unsolved

“…Several mechanisms have reported the causes of coronary spasm, such as the abnormal response of the autonomic nervous system[ 13 ], endothelial dysfunction of the coronary artery or systemic peripheral vasculature[ 14 - 17 ], abnormal or hyper-reaction of vascular smooth muscles[ 18 - 20 ], and other factors such as a magnesium deficiency[ 21 , 22 ], inheritance[ 23 ], or specific anatomy of the coronary artery[ 24 - 27 ]. Naturally, the mechanism of coronary spasm may not be always simple, but may be also multi-factorial.…”

“…Recently, some interest has also focused on the specific coronary anatomy in VSA patients (Table 1 ): The presence of myocardial bridge (MB), which is characterized by the systolic narrowing of the epicardial coronary artery because of myocardial compression during systole[ 24 - 27 ]. Furthermore, coronary spasm occurs more frequently at the MB, which is in part mediated by coronary vascular dysfunction, including endothelium-dependent and endothelium-independent dysfunctions, at the MB segments.…”

“…Recently, coronary spasm has been considered one of the causes of heart failure with reduced ejection fraction[ 10 - 12 ]. Mechanisms responsible for coronary spasm were reported to be the abnormal response of the autonomic nervous system[ 13 ], endothelial dysfunction[ 14 - 17 ], abnormal or hyper-reaction of vascular smooth muscles[ 18 - 20 ], and other factors, such as magnesium deficiency[ 21 , 22 ], inheritance[ 23 ], or specific anatomy of the coronary artery[ 24 - 27 ]. In addition, the diagnosis and treatment of coronary spasm were based on the guidelines of coronary spasm[ 28 , 29 ].…”