Discussion
The normal course of coronary arteries is between the pericardium and epicardium, the two most outer layers of the heart. However, if a portion of epicardium is encased by myocardial fibers it is called myocardial bridge. It can occur in any coronary artery but the most commonly involved one is the left anterior descending artery (LAD); the least commonly affected coronary arteries are left circumflex and right coronary arteries.( 6,7)
It was previously considered as a benign cardiovascular anomaly, but because of increasing evidences of its complications it is no more a benign disease, in at least subset of patients. Although it is benign and most patients are asymptomatic, some are complicated by stable or unstable angina, vasospastic angina, acute coronary syndromes, AV blocks, arrthytima, and sudden cardiac death. (8- 11)
It is not uncommon for the diagnosis of MB to be delayed. This could be because of the varied clinical presentations, and lack of advanced imaging modality in poor settings. Our patient visited several health facilities before she was referred to our hospital, where the diagnosis was made. This could be as a result of lack of awareness about the MB, and unavailability of advanced imaging modalities.
Although there are cases reports of MB complications in young female patients (12), most of these complications were observed in young male patients. Our patient is a 38 years young female patient; this makes our patient a unique.
MB induces acute coronary syndromes via several mechanisms including coronary spasm, thrombosis, coronary dissection, or development of focal atherosclerosis proximal to the myocardial bridging. (13)
Diagnosis of MB can differ significantly depending on the imaging modality employed to identify these variants. The prevalent methods frequently examined to ascertain prevalence in the general population comprise coronary angiography (CA), coronary computed tomography angiography (CCTA), and autopsy studies. (14). our patient was examined with CT- coronary angiography, which confirmed the diagnosis.
Currently, there are no universal guidelines for the treatment of MB. Most experts agree that the first line treatment for individuals experiencing symptoms of myocardial bridge typically should be medications like beta-blockers or non-dihydropyridine calcium channel blockers. It is advisable to steer clear of nitrates as they could exacerbate symptoms. It is also advised that surgical interventions should be pursued for patients who don’t respond to medical therapy. Surgical interventions, such as myotomy, intracoronary stenting and coronary artery bypass graft surgery have been employed for persistent symptoms, yet the long-term prognosis remain uncertain. Another treatment option include stent placement. (15, 16). Our patient was treated with beta blocker, and calcium channel blockers without symptomatic response. She was counseled on surgical intervention options.