Myocardial Bridging: A Case Presentation of Atypical Chest Pain Syndrome in a Young Woman

Mid-ventricular Takotsubo Cardiomyopathy With Coexisting Myocardial Bridge

Typical takotsubo cardiomyopathy (TCM) is a reversible form of myocardial injury that presents with a characteristic ballooning abnormality of the left ventricular apex. Typical TCM has been associated with myocardial bridging; however, mid-ventricular variant TCM has not. We describe a rare case of mid-ventricular variant TCM with a coexisting left anterior descending artery myocardial bridge and discuss management strategies. Furthermore, we propose potential pathophysiological mechanisms that may contribute to the symptomatic presentation of both conditions as a manifestation of common etiological factors.

Update review on myocardial bridging: New insights

Myocardial bridging (MB) is a common congenital abnormality that remains asymptomatic in a large proportion of patients. The peak of clinical manifestation occurs during the third and fourth decades of life. MB provokes myocardial ischemia through different mechanisms including supply-demand mismatch, endothelial dysfunction, coronary microvascular dysfunction and external mechanical compression. The association between MB and atherosclerotic disease is controversial. Recent studies established a significant association of MB with myocardial infarction and non-obstructive coronary artery disease. The first line medical treatment is based on beta-blockers and calcium channel blockers. Ivabradine is used in second line therapy. Invasive approaches involving percutaneous coronary intervention, coronary artery bypass graft and myotomy are performed in patients with symptoms refractory to maximally tolerated medical treatment. The choice of revascularization technique depends on anatomical characteristics, clinical condition and physician experience. Available data derived from anecdotal evidence view the lack of randomized clinical trials.

A Young Adult With Myocardial Bridging: A Case Report

Myocardial bridging (MB) is a condition where the coronary artery is intramural instead of its natural course through the epicardium. Here, we present a case of a 25-year-old male without any medical history who presented with intermittent substernal chest discomfort on exertion. EKG was suggestive of ST changes in leads V1-V4 with right axis deviation. A left heart catheterization revealed myocardial bridging of the midportion of the left anterior descending artery. Myocardial bridging is commonly not associated with severe complications. However, it is imperative to diagnose it appropriately, especially in cases of chest pain, and provide immediate treatment to prevent mortality and morbidity.

Worsening of Angina Following Nitroglycerin Administration: A Case Report of the Interplay With Undiagnosed Myocardial Bridge

Myocardial bridge (MB) is a congenital abnormality where part of a coronary epicardial artery runs under the myocardium fibers and is compressed in systole; this becomes more pronounced when nitroglycerin (NTG) is administered. In this report, we describe the case of a 40-year-old African American man who presented with chest pain that did not respond to NTG or isosorbide mononitrate and was only partially relieved by narcotics. His past medical history was significant for coronary artery disease (CAD) with a stent into the left anterior descending artery (LAD) several months prior, hypertension, hyperlipidemia, paroxysmal atrial fibrillation, sick sinus syndrome, permanent pacemaker, pulmonary embolism, and cerebral vascular accident. No explanation for his angina was found either in the previous outpatient left heart catheterization (LHC) procedures demonstrating LAD stent patency or initial chest pain workup upon admission. Functional LHC procedure with adenosine infusion and acetylcholine provocation demonstrated endothelial dysfunction with notable epicardial spasm and MB of the LAD that worsened with NTG. Cardiology advised dual antiplatelet therapy and a statin as part of treatment for CAD and a calcium channel blocker with a bradycardic effect (e.g., diltiazem, verapamil) for the MB and coronary vasospasm, and avoidance of NTG and long-acting nitrates (e.g., isosorbide mononitrate), which can cause reflex tachycardia and worsen angina from MB. A selective serotonin reuptake inhibitor was added for increased cardiac nociception. The patient's pain resolved, and he was discharged. MB is an important alternate etiology to consider when chest pain does not respond to NTG administration for adjustment of treatment modalities. The initial treatment for this patient's pain with NTG likely exacerbated symptoms by reducing intrinsic coronary wall tension and subsequently increasing reflex sympathetic stimulation of contractility of the left ventricular myocardium, which can, in turn, increase anginal symptoms and ischemia.

Myocardial Bridging: Two Different Clinical Presentations in Young Males Involving Left Anterior Descending Coronary Artery

Myocardial bridging is a rare anatomical variant that can lead to detrimental cardiac consequences when undiagnosed and untreated. This rare variant can induce anginal-type symptoms due to disrupted blood flow to the myocardium during systole. The patients presented in this report of two cases had previously undiagnosed myocardial bridging of the left anterior descending artery, however clinically, they presented quite differently. Here we present two cases discussing the course of diagnosis and treatment of myocardial bridging of these two patients. The goal of this case report is to highlight the significant cardiovascular injuries that can be a result of undiagnosed myocardial bridging.

Implications of Myocardial Bridge on Coronary Atherosclerosis and Survival

Background: In this study, we aimed to describe the impact of MBs on atherosclerosis and survival, in patients with coronary artery disease (CAD). Methods: We retrospectively studied 1920 consecutive patients who underwent conventional coronary angiography for suspected CAD. Atherosclerotic load (AL), defined as the sum of degrees of stenosis, and general atherosclerotic load (GAL), representing the sum of AL, were compared between patients with MB and a control group without MB; patients in these groups were similar in age and sex. We assessed survival at 10 years after the last enrolled patient. Results: Prevalence of MB was 3.96%, predominantly in the mid-segment of left anterior descendent artery (LAD). In the presence of MB, GAL was lower (158.1 ± 93.7 vs. 205.3 ± 117.9, p = 0.004) with a lesser AL in the proximal (30.3 ± 39.9 vs. 42.9 ± 41.1, p = 0.038) and mid-segments (8.1 ± 20.0 vs. 25.3 ± 35.9, p < 0.001) of LAD. Based on a Multinominal Logistic Regression, we found that the presence of MB on LAD (regardless of its location on this artery) is a protective factor against atherosclerotic lesions, decreasing the probability of significant stenosis, especially of those ≥70%, on the entire artery (B −1.539, OR 4660; 95% CI = 1.873−11.595, p = 0.001) and on each of its segments as well: proximal LAD (B −1.275, OR 0.280; 95% CI = 0.015−5.073; p = 0.038), mid-LAD (B −1.879, OR 6.545; 95% CI = 1.492−28.712; p = 0.013) and distal LAD (B −0.900, OR 2.459, 95% CI = 2.459−2.459, p = 0.032). However, 10-year survival was similar between groups (76.70% vs. 74.30%, p = 0.740). Conclusion: The presence of MB on LAD proved to be a protective factor against atherosclerosis for the entire artery and for each of its segments, but it does not influence long-term survival in patients with CAD.