Myocardial bridging: A 'forgotten' cause of acute coronary syndrome - a case report

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.

A Morphological Study of Myocardial Bridges in the Fetal Heart

Introduction:Myocardial bridges (MB) are congenital anomalies of hearts observed as muscle fibers covering epicardial branches of the coronary artery. The left anterior descending artery (LAD) was found to be commonly showing myocardial bridges (MBs). Clinically, MBs were claimed to cause varied symptomatology. The data on the morphology and prevalence of MBs in fetuses was limited, despite the commonly accepted congenital origin. Material and methods:Fetal hearts obtained from 37 fetuses from the donation program were used. The hearts were dissected out from the thorax by standard dissection procedure. The pericardium and epicardium were dissected. The coronary arteries were delineated, and MBs were observed and noted. The coronary artery segment having MBs, its distance from the ostium as well as the direction and length of the MBs were studied. Results:The MBs were observed in 20 out of 37 fetal hearts studied over the left anterior descending, right coronary, posterior interventricular and circumflex arteries. The mid or distal part of the coronary arteries frequently exhibited MBs. The mean length of the MB was 4.2 mm, with MBs being situated about 1.5 cm away from the coronary ostium. The oblique pattern of MB was more frequently noted. Conclusion:The morphology and prevalence of fetal MBs showed common occurrence in the LAD artery, with a predominant oblique morphological pattern.

Case report: A fatal case of myocardial infarction due to myocardial bridge and concomitant vasospasm: the role of stress gated SPECT

Introduction

Although most cases of myocardial bridge (MB) are clinically benign, sometimes it can be one of potential threats of myocardial infarction (MI) and life-threatening arrhythmia. In the present study, we present a case of ST-segment elevation MI caused by MB and concomitant vasospasm.

Case Presentation

A 52-year-old woman was brought to our tertiary hospital due to resuscitated cardiac arrest. Because the 12-lead electrocardiogram indicated ST-segment elevation MI, coronary angiogram was promptly commenced, which showed near-total occlusion at the middle portion of left anterior descending coronary artery (LAD). After intracoronary nitroglycerin administration, this occlusion was dramatically relieved, however, systolic compression at this site remained, indicative of myocardial bridge (MB). Intravascular ultrasound also showed eccentric compression with a "half-moon" sign, which is consistent with MB. Coronary computed tomography also showed a bridged coronary segment surrounded by myocardium at the middle portion of LAD. To assess the severity and extent of myocardial damages and ischemia, myocardial single photon emission computed tomography (SPECT) was additionally conducted, showing a moderate fixed perfusion defect around the cardiac apex, suggesting MI. After receiving optimal medical therapy, the patient's clinical symptoms and signs were improved then the patient was discharged from the hospital successfully and uneventfully.

Conclusion

We demonstrated a case of MB-induced ST-segment elevation MI which was confirmed with its perfusion defects via myocardial perfusion SPECT. There have been proposed a number of diagnostic modalities to examine its anatomic and physiologic significance. Among them, myocardial perfusion SPECT can be available as one of useful modalities to evaluate the severity and extent of myocardial ischemia in patients with MB.

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.

Myocardial Bridging, the Hidden Risk Factor for Ischemia

Myocardial bridging is an uncommon cause of a quite common emergency department complaint for chest pain and is often associated with left ventricular hypertrophy. We present a case of an otherwise healthy middle-aged U.S. military service member who presented with acute coronary syndrome which was ultimately determined to be the result of myocardial bridging.

Incidental Intramyocardial Bridging in a Myocarditis Patient Presenting With Focal ST Segment Depressions

Myopericarditis is an entity known to present with typical symptoms of viral prodrome and diffuse ST elevation (STE) and/or PR depressions on electrocardiogram (EKG). Atypical presentations of myocarditis such as focal STE have been cited in the literature, reflecting true coronary ischemia. However, myocarditis or pericarditis presenting with focal ST depressions is rarely seen. Myocarditis is usually overlooked as a differential for ST depressions seen on EKGs; hence, the case we present in this report highlights the importance of nonischemic causes presenting as ischemic changes on EKG. This case is unique as we have postulated a possible explanation for this finding.

This report discusses the case of a young patient with myopericarditis presenting with focal ST depressions. This patient was also incidentally found to have intramyocardial bridging, usually a benign finding, on cardiac catheterization (which is shown in the case report). Our hypothesis is that the inflammation due to myocarditis in this patient led to inflammation of intramyocardial vessels, presenting as ST depressions. Since intramyocardial bridging is a common anomaly, we propose the question as to whether this could be a risk factor for sudden cardiac death and if it depends on the characteristic of the intramyocardial vessel. We would like to emphasize on the atypical presentations of this usual condition, a possible explanation for this finding, and the need for further testing for risk stratification in patients with this anomaly.

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

Patient: Female, 29-year-old

Final Diagnosis: Myocardial bridging

Symptoms: Chest pain

Medication: —

Clinical Procedure: Coronary angiography • CT scan • echocardiography

Specialty: Cardiology • General and Internal Medicine

An Updated Review on Myocardial Bridging

Myocardial bridging is a congenital coronary anomaly with normal epicardial coronary artery taking an intra-myocardial course also described as tunneled artery. The majority of patients with this coronary anomaly are asymptomatic and generally it is a benign condition. However, it is an important cause of myocardial ischemia, which may lead to anginal symptoms, acute coronary syndrome, cardiac arrhythmias and rarely sudden cardiac death. There are numerous studies published in the recent past on understanding the pathophysiology, diagnostic and management strategies of myocardial bridging. This review highlights some of the recent updates in the diagnosis and management of patients with myocardial bridging. We discuss the role of various non-invasive and invasive diagnostic methods to evaluate functional significance of bridging. In addition, role of medical therapy such as beta-blockers, percutaneous coronary intervention with stents/bioresorbable scaffolds and surgical unroofing in patients unresponsive to medical therapy is highlighted as well.

Troponin release after exertional vasovagal syncope

Troponin release following exertional vasovagal syncope has not previously been reported. A young man was investigated after being admitted twice with exertional syncope, each time followed by a 10-fold spike in troponin I over 24 h. Treadmill exercise tests reproduced his symptoms and demonstrated a vasovagal mechanism. During recovery, despite lying supine, he remained hypotensive for 5 min, with profound bradycardia and ST segment depression. We suspected that intense cardiovagal neural activity may have caused the troponin leak.