MYOCARDIAL BRIDGE: A CLINICAL REVIEW OF DIAGNOSTIC, PROGNOSTIC AND THERAPEUTIC IMPLICATIONS
Subhash Gyawali and Hai-Rong Wang*
ABSTRACT
Myocardial bridge (MB) is a congenital coronary anomaly, in which a segment of coronary artery travels into the myocardium instead of the normal epicardial course. Although MB can be found in any coronary artery, the most common site of myocardial bridging is in the mid left anterior descending (LAD) coronary artery. The involvement of other coronary arteries, such as the right coronary artery (RCA), diagonal, ramus, and the marginal branch, are less common. The characteristic feature of MB is that with each systole, the coronary artery is compressed. In the vast majority of cases, myocardial bridge remains clinically silent, but sometimes the patient with myocardial bridge may present with symptoms, such as exertional chest pain, myocardial infarction, arrhythmias and even sudden death. The first-line therapy of symptomatic bridging remains medical treatment with beta blockers and calcium-channel blockers, but nitrates are contraindicated due to secondary tachycardia and hypercontractility. Patients who respond poorly to the medical treatment, warrant a surgical intervention. Surgical intervention includes myotomy, intracoronary stent and coronary artery bypass grafting surgery (CABG). For the symptomatic patients, myotomy is preferred surgical procedure. Use of coronary stents is limited due to complications and unsatisfactory long-term results.
Keywords: Myocardial bridge, coronary artery, myocardial infarction, arrhythmias, myotomy.
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