Presentation of important studies, case studies and reports about myocardial bridging
Studies about myocardial bridging
Relationship between Different Degrees of Compression and Clinical Symptoms in Patients with Myocardial Bridge and the Risk Factors of Proximal Atherosclerosis
To explore the relationship between different degrees of compression and clinical symptoms in patients with the myocardial bridge and the risk factors of proximal atherosclerosis.
The more severe the compression of the myocardial bridge, the greater the risk of cardiovascular events for patients and the higher the incidence of atherosclerotic stenosis in the proximal part of the myocardial bridge. In addition, the occurrence of atherosclerosis in the proximal coronary artery of the myocardial bridge may be affected by age, hypertension, Noble grade, and CRP level.
Myocardial bridge characteristics and coronary atherosclerotic markers
The clinical signifi cance of myocardial bridge (MB) on the whole coronary system and coronary atherosclerosis is still a matter of debate. This study aimed to investigate the possible association between MB characteristics (length, depth, proximal stenosis presence and site) with coronary atherosclerotic markers (coronary artery calcifi cation [CAC], plaque, stenosis and pericardial fat volume [PFV]).
Impact of Diastolic Vessel Restriction on Quality of Life in Symptomatic Myocardial Bridging Patients Treated With Surgical Unroofing: Preoperative Assessments With Intravascular Ultrasound and Coronary Computed Tomography Angiography
Despite optimal medical therapy, a myocardial bridge (MB) can cause life-limiting symptoms in a subset of patients. While surgical unroofing has been shown to improve MB-derived refractory angina, diagnostic indices of clinical symptoms and predictors of improvement following surgery are yet to be elucidated.
Restricted arterial relaxation in diastole, rather than the degree of systolic compression or extent of an MB, seems to be the primary determinant of clinical symptoms and improvement in quality of life following surgical unroofing.
Myocardial Bridging Unmasks as an Acute Coronary Syndrome from Dehydration
A 50-year-old male presented for loss of consciousness. He was initially treated with intravenous epinephrine and fluids, and an electrocardiogram (ECG) displayed an ST-segment elevation in lead aVR with global ST-segment depressions. A subsequent left heart catheterization revealed that the middle segment of the left anterior descending artery (LAD) demonstrated severe stenosis during systole but would become patent during diastole, which was suggestive of myocardial bridging. After stopping the epinephrine and increasing the fluid infusion, the ECG changes rapidly resolved. The patient had later admitted to significant dehydration all day. Myocardial bridging is a congenital anomaly in which a coronary artery segment courses through the myocardium instead of the usual epicardial surface. Occasionally, myocardial bridging may present similarly to acute coronary syndrome in severe dehydration or hyperadrenergic states. The diagnosis can be made through coronary angiography, which reveals a dynamic vessel obstruction pattern corresponding with the cardiac cycle. Long-term effects may also include accelerated atherosclerosis. Treatment consists of reversing precipitating causes during acute presentations and decreasing the risk of coronary artery disease on a chronic basis.
Takotsubo Cardiomyopathy Coexisting with Acute Pericarditis and Myocardial Bridge
Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy that occurs primarily in postmenopausal women. It mimics clinical picture of acute coronary syndrome with nonobstructive coronary arteries and a characteristic transient left (or bi-) ventricular apical ballooning at angiography. The exact pathogenesis of TCM is not well recognized. Hereby we present an unusual case of TCM that presents with signs and symptoms of acute pericarditis and was also found to have a coexisting coronary muscle bridge on coronary angiography. We discuss the impact of these associations in better understanding of the pathogenesis of TCM.
Myocardial bridge-related coronary heart disease: Independent influencing factors and their predicting value
Myocardial bridge (MB) will compress the mural coronary artery (MCA) during the systole and cause myocardial ischemia. In the diagnosis of coronary heart disease (CHD), because the structure of MB is difficult to be observed by coronary angiography (CAG), the clinical study of the influence of MB on CHD is lacking. With the advancement of computed tomography coronary angiography technology, detailed observations of the MB anatomy have realized.
Aim: To explore the main influencing factors of MB-related CHD and to find potential indicators for predicting MB-related CHD.
Clinical Outcomes of Surgical Unroofing of Myocardial Bridging in Symptomatic Patients
There is a paucity of data regarding results of surgical management of myocardial bridging. Our objective was to evaluate the clinical outcomes of unroofing procedures in patients with myocardial bridging of the left anterior descending (LAD) coronary artery who had chest pain refractory to medical therapy.
Myocardial unroofing can be performed safely in patients with chest pain and isolated LAD coronary artery myocardial bridging. However, patients should be aware of the potential for recurrent nonischemic chest pain and continued medical therapy despite relief of coronary compression.
Myocardia ischemia associated with a myocardial bridge with no significant atherosclerotic stenosis
Myocardial bridge refers to the myocardial tissue with which the coronary artery is partly covered. Though it has long been regarded to be benign, patients with myocardial bridges may present with myocardial ischemia, acute coronary syndromes, coronary spasm, sudden cardiac arrest or even sudden death.
These cases indicated that cardiac events in patients with myocardial bridge may be associated with coronary spasm, myocardial supply/demand mismatch or cardiac arrest.
Cardiovascular consequences of myocardial bridging: A meta-analysis and meta-regression
Myocardial bridging, a congenital abnormality in which a coronary artery tunnels through the myocardial fibres was usually considered a benign condition. Many studies suggested a potential hemodynamic significance of myocardial bridging and some, usually case reports, implied a possible correlation between it and various cardiovascular pathologies like acute myocardial infarction, ventricular rupture, life-threatening arrhythmias, hypertrophic cardiomyopathy, apical ballooning syndrome or sudden death. The main objective of this article is to evaluate whether myocardial bridging may be associated with significant cardiac effects or if it is strictly a benign anatomical variation. To this purpose, we performed a meta-analysis (performed using the inverse variance heterogeneity model) and meta-regression, on scientific articles selected from three main databases (Scopus, Web of Science, Pubmed). The study included 21 articles. MB was associated with major adverse cardiac events – OR = 1.52 (1.01–2.30), and myocardial ischemia OR = 3.00 (1.02–8.82) but not with acute myocardial infarction, cardiovascular death, ischemia identified using imaging techniques, or positive exercise stress testing. Overall, myocardial bridging may have significant cardiovascular consequences (MACE, myocardial ischemia). More studies are needed to reveal/refute a clear association with MI, sudden death or other cardiovascular pathologies.
Functional Assessment of Myocardial Bridging With Conventional and Diastolic Fractional Flow Reserve: Vasodilator Versus Inotropic Provocation
Functional assessment of myocardial bridging (MB) remains clinically challenging because of the dynamic nature of the extravascular coronary compression with a certain degree of intraluminal coronary reduction. The aim of our study was to assess performance and diagnostic value of diastolic‐fractional flow reserve (d‐FFR) during dobutamine provocation versus conventional‐FFR during adenosine provocation with exercise‐induced myocardial ischemia as reference.
Outcome of Repair of Myocardial Bridging at the Time of Septal Myectomy
Myocardial bridging describes systolic compression of the muscular investment of a portion of an epicardial coronary artery. We evaluated the outcome of muscular bridge unroofing of the left anterior descending artery at the time of septal myectomy in patients with hypertrophic cardiomyopathy. Myocardial unroofing can be performed safely at the time of septal myectomy for left ventricular outflow tract obstruction. Angina was improved, but we found no difference in late survival compared with patients who had myocardial bridging and myectomy alone. Unroofing should be considered in patients with angina who have significant left anterior descending artery bridging and require myectomy.
Anatomic properties of myocardial bridge predisposing to myocardial infarction
A myocardial bridge (MB) that partially covers the course of the left anterior descending coronary artery (LAD) sometimes causes myocardial ischemia, primarily because of hemodynamic deterioration, but without atherosclerosis. However, the mechanism of occurrence of myocardial infarction (MI) as a result of an MB in patients with spontaneously developing atherosclerosis is unclear. n the proximal LAD with an MB, MB muscle index is associated with a shift of coronary disease more proximally, an effect that may increase the risk of MI.
Accuracy of a novel stress echocardiography pattern for myocardial bridging in patients with angina and no obstructive coronary artery disease – A retrospective and prospective cohort study
Myocardial bridge (MB) may cause angina in patients with no obstructive coronary artery disease (CAD). We previously reported a novel stress echocardiography (SE) pattern of focal septal buckling with apical sparing in the end-systolic to early-diastolic phase that is associated with the presence of an MB. We evaluated the diagnostic accuracy of this pattern, and prospectively validated our results. Presence of focal septal buckling with apical sparing on SE is an accurate predictor of an MB in patients with angina and no obstructive CAD. This pattern can reliably be used to screen patients who may benefit from advanced non-invasive/invasive testing for an MB as a cause of their angina.
Surgical Unroofing of Hemodynamically Significant Left Anterior Descending Myocardial Bridges
Left anterior descending artery myocardial bridges (MBs) range from clinically insignificant incidental angiographic findings to a potential cause of sudden cardiac death. Within this spectrum, a group of patients with isolated, symptomatic, and hemodynamically significant MBs despite maximally tolerated medical therapy exist for whom the optimal treatment is controversial. We evaluated supraarterial myotomy, or surgical unroofing, of the left anterior descending MBs as an isolated procedure in these patients. Surgical unroofing of carefully selected patients with MBs can be performed safely as an independent procedure with significant improvement in symptoms postoperatively. It is the optimal treatment for isolated, symptomatic, and hemodynamically significant MBs resistant to maximally tolerated medical therapy.
Coronary artery bridging as an etiology for non-atherosclerotic myocardial infarction: A review of literature and case history
Myocardial infarction may occur without atherosclerotic lesions discernible by coronary angiography. The impact of this phenomenon may not be appreciated by many clinicians largely because of a priori assumptions that patients who present with a history of MI or angina syndrome are victims of atherosclerosis and fit well into mainstream management ranging from acute care to rehabilitation. In the absence of atherosclerosis, myocardial infarction may result from several exacerbated by chronic hypoperfusion if the culprit artery has a course within the myocardium rather than a more epicardial course. These vessels, called tunnelled arteries, are typically traversed by thick bundles of muscle fibres that comprise a myocardial bridge. They are characterized by chronically abnormal hemodynamics that are prone to exacerbation, leading to anginal symptoms and myocardial infarction. A case history is presented that describes the presentation, medical evaluation and treatment, and rehabilitation of a patient with non-atherosclerotic MI attributed to a myocardial bridge. It is followed by a review of the pathophysiology of this medical problem and efficacy of various treatments. Rehabilitation considerations that apply to patients with a tunnelled coronary artery are discussed.
Myocardial Bridges a Forgotten Condition: A Review
Myocardial Bridging (MB) is a congenital anomaly in which a segment of a coronary artery takes a „tunneled“ intramuscular course under a „bridge“ of overlying myocardium. The first reference of MB in coronary arteries, the association with angina and anatomically as referred by Reyman in 1737. Considered a „benign“ finding since the myocardial bridge causes coronary artery narrowing during systole therefore myocardial bridges should not compromise blood supply to the musculature during diastole. The Left Anterior Descending coronary (LAD) is the most frequently affected vessel (70% in an autopsy series) and in some cases hearts contain more than one bridge, affecting the same vessel or different coronaries.
MB also has been associated with angina, myocardial infarction, arrhythmia, depressed left ventricular function, left bundle branch block, myocardial stunning, apical ballooning syndrome, early death after cardiac transplantation, and sudden death. The MB is a clinical condition with several possible manifestations, and its clinical relevance is debated.
Unusual Sign from an Unusual Cause: Wellens’ Syndrome due to Myocardial Bridging
It is vital to recognize correctly, chest pain of cardiac etiology. Most commonly, it is because of blood supply-demand inequity in the myocardium. However, the phenomenon of myocardial bridging as a cause of cardiac chest pain has come to attention reasonably recently. Herein, a coronary artery with a normal epicardial orientation develops a transient myocardial course. If the cardiac muscle burden is substantial, the respective artery gets compressed during each cycle of systole, thereby impeding blood flow in the artery. Hence, myocardial bridging has been attributed to as a rare cause of angina. In this case report, the authors discuss a patient in whom myocardial bridging turned out to be an elusive cause of angina. We wish to underscore the importance of being clinically mindful of myocardial bridging when assessing a patient with angina.
Kounis Syndrome together with Myocardial Bridging Leading to Acute Myocardial Infarction at Young Age
Kounis syndrome, also named as “allergic angina syndrome,” is a diagnosis in which exposure to an allergen causes mostly coronary spasm and rarely plaque rupture, resulting in ischemic myocardial events. Myocardial bridging is defined as an intramural segment of a coronary artery and its systolic compression by overlying fibers. Myocardial bridging generally has a benign prognosis and mostly affects the mid portion of left anterior descending coronary artery. However, some cases with myocardial ischemia, infarction, and sudden death have also been reported. A 17-year-old boy presented to the clinic with acute anterolateral myocardial infarction after having first dose of clindamycin and diagnosed as Kounis syndrome. Further diagnostic workup of the patient showed myocardial bridging at the mid left anterior descending artery. In this report, we present the combination of Kounis syndrome and myocardial bridging leading to myocardial infarction at young age.
Myocardial Bridging: Contemporary Understanding of Pathophysiology With Implications for Diagnostic and Therapeutic Strategies
Patients with myocardial bridging are often asymptomatic, but this anomaly may be associated with exertional angina, acute coronary syndromes, cardiac arrhythmias, syncope, or even sudden cardiac death. This review presents our understanding of the pathophysiology of myocardial bridging and describes prevailing diagnostic modalities and therapeutic options for this challenging clinical entity.
Characteristics of stress tests and symptoms in patients with myocardial bridge and coronary artery spasm
A relationship between coronary artery spasm (CAS) and myocardial bridge (MB) has been noticed. This study was designed to investigate the differences of stress tests and symptoms between CAS patients with or without MB.
MB might predispose to CAS in which endothelial dysfunction may play a part. CAS patients with MB usually present mixed chest pain and positive stress tests as well as reversal redistribution on myocardial scintigraphy whereas CAS patients without MB displayed chest pain at rest, negative stress test and reversal redistribution.
Myocardial Bridging in Adults
A 66-year-old male rower with a history of hypertension and dyslipidemia presented with exertional chest pain and palpitations. He denied symptoms or limitations with activities of daily living. He engaged in vigorous exercise daily and his goal was to continue his current exercise routine without exercise restrictions.
The Myocardial Bridge: Potential Influences on the Coronary Artery Vasculature
A myocardial bridge (MB) is an anatomical abnormality of the coronary artery and is characterized by the systolic narrowing of the epicardial coronary artery caused by myocardial compression during systole. An MB is frequently observed on cardiac computed tomography or coronary angiography and generally appears to be harmless in the majority of patients. However, the presence of MB is reportedly associated with abnormalities of the cardiovascular system, including coronary artery diseases, arrhythmia, certain types of cardiomyopathy, and cardiac death, indicating that MB serves a pivotal role in the occurrence and/or development of such cardiovascular events. Recently, there has been an increasing interest in the coexistence of MB and coronary spasm in research due to opposing aspects regarding their treatments. For example, monotherapy using β-blockers, which are effective in patients with MB, may worsen symptoms in patients with coronary spasm. By contrast, nitroglycerin, which is an effective treatment option for coronary spasm, may worsen symptoms in patients with MB. This review focuses on the pathophysiology and diagnosis of MB and MB-related cardiovascular diseases, including coronary spasm, and on the treatment strategies for MB.
Death Due to Myocardial Bridging
Myocardial bridging is a congenital coronary pathology described as a segment of coronary artery which courses through the myocardial wall beneath the muscle bridge. Although the myocardial bridging prognosis is benign, have been also reported sudden death in medical literature. ¬A 30-year-old married woman was found dead at her home. After local prosecutors‘ investigation the death was declared as suspicious and forensic autopsy was obliged. The left anterior descending coronary artery was detected embedded deeply in the myocardium 2 cm from its coronary ostial origin. There were no other pathology to explain death. We analyzed sudden death case occurred because of myocardial bridging and the pathophysiological mechanisms in the light of medico-legal literature.
Extensive unroofing of myocardial bridge: A case report and literature review
Myocardial bridge is defined as a segment of a coronary artery that takes an intramyocardial course. The presence of myocardial bridge has been observed in as many as 40%-80% of cases on autopsy, angiographically from 0.5% to 16.0%, and often asymptomatic. However, it has been associated with angina, coronary spasm, myocardial infarction, arrhythmias, syncope, sudden cardiac arrest, and death. Conflicting opinions exist on the timing of surgical intervention for myocardial bridge. Management decision on myocardial bridge remains controversial. This is a case of the longest symptomatic myocardial bridge, with a subsequent improvement post unroofing.
MYOCARDIAL BRIDGE MUSCLE INDEX (MMI): A MARKER OF DISEASE SEVERITY AND ITS RELATIONSHIP WITH ENDOTHELIAL DYSFUNCTION AND SYMPTOMATIC OUTCOME IN PATIENTS WITH ANGINA AND A HEMODYNAMICALLY SIGNIFICANT MYOCARDIAL BRIDGE
Myocardial bridge (MB) muscle index (MMI), the product of MB depth x length, is suggestive of severity of an MB. MBs are also associated with endothelial dysfunction. We studied the relationship of MMI with endothelial function, and its effect on symptomatic outcome in patients undergoing surgical unroofing for a hemodynamically significant MB. The presence of a higher MMI and endothelial dysfunction should be taken into account when discussing with patients the expected symptomatic improvement following surgical unroofing for an MB.
Significance of anatomical properties of myocardial bridge on atherosclerosis evolution in the left anterior descending coronary artery
yocardial bridge (MB) is frequently detected in the left anterior descending coronary artery (LAD), and LAD intima under MB is significantly spared from atherosclerotic evolution. Significance of anatomical features of MB on the extent of atherosclerosis of LAD was histomorphometrically investigated. Full-length 200 LADs with MB and 100 control LADs without MB were cross-sectioned at 5 mm intervals, and atherosclerosis ratio and intimal lesion types were evaluated. In cases with MB located within 5 cm from the left coronary ostium, atherosclerosis ratio in the proximal part of LAD was significantly lower than in control group, but, in cases with MB locating more than 5 cm from the ostium, atherosclerosis ratio in this part was similar to that in control cases. MB thickness was significantly correlated with its length, and the longer the MB the more proximally it tended to be located in LAD. Atherosclerosis ratio under MB was lower in cases with thick or long MBs than in cases with thinner or shorter MBs. In addition, intimal lesion in segments proximal to MB tended to be eccentric. Our results suggest that these anatomical properties of MB are the critical modulators for atherosclerosis evolution in the entire course of LAD.
Myocardial Bridge Study to Assess Testing and Outcomes, Develop Guidelines
A study underway at Cleveland Clinic aims to close gaps in the literature regarding the testing, management and long-term outcomes of patients with myocardial bridging. This common congenital lesion involves partial or complete encasement of coronary arteries, usually the left anterior descending artery (LAD), in the myocardium. The lesions vary in length and depth and were once thought to be primarily benign. More recent studies have challenged that assertion, and Cleveland Clinic’s ongoing Myocardial Bridge and Anomalous Coronary Study seeks to create a more accurate picture of how to optimally identify, evaluate and manage the condition.
A Challenging Combination: Anomalous Left Anterior Descending Coronary Artery, Myocardial Bridging, and Endothelial Dysfunction
50 years old female patient with a medical history of hypertension presented to the clinic with chest pain, palpitations, and dyspnea on exertion of 2 years duration. Extensive workup in search of the culprit etiology of her chest pain revealed a challenging combination of an anomalous left anterior descending artery with myocardial bridging and endothelial dysfunction. She was treated medically with long acting nitrates, L-arginine and calcium channel blockers, and remains asymptomatic after 12 months of follow up.
Nitroglycerine Induced Acute Myocardial Infarction in a Patient with Myocardial Bridging
Muscle overlying an intramyocardial segment of a coronary artery is termed a myocardial bridge. The intramyocardial segment, the tunneled artery, is compressed during systole. The condition is generally benign but may occasionally cause myocardial ischemia, infarction, arrhythmia, or sudden cardiac death. We present a case regarding a 52-year-old man with exercise-induced angina who was diagnosed with a myocardial bridge overlying the left anterior descending artery. He was initially treated with beta-blockers and later received coronary bypass graft surgery.
Is coronary artery bypass grafting an acceptable alternative to myotomy for the treatment of myocardial bridging?
A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was ‘Is CABG an effective alternative for the treatment of myocardial bridging?’ Altogether, only six papers were identified using the reported search that represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes, and results of these papers are tabulated; these studies reported the outcome of myotomy and coronary artery bypass grafting (CABG) for myocardial bridging. All of these studies were retrospective reports of the results of surgical intervention in patients with myocardial bridging. They showed that the incidence of myocardial bridging was less than 1–1.5% in patients with angina requiring angiography, and 7–9% of these patients had refractory angina despite medical treatment and required surgery. The evidence on the treatment of this congenital condition that mainly affects the middle segment of left anterior descending artery is limited, and there are no treatment guidelines currently available. Stenting of the tunnelled segment has shown high failure rates in approximately half of the cases. Current evidence in the literature suggests that surgery is the mainstay treatment for myocardial bridging.
Assessment of Myocardial Bridge and Mural Coronary Artery Using ECG-Gated 256-Slice CT Angiography: A Retrospective Study
Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA) might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA) is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%). Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%). The average diameter change of MCA in LAD2 from systole phase to diastole phase was mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.
Robotic-assisted surgical myotomy in a 27-year-old man with myocardial bridging of the left anterior descending coronary artery
Myocardial bridging (MB) is a frequent condition usually considered benign but it may be associated with myocardial ischemia. When bridging is symptomatic, therapeutic options are numerous and in the absence of guidelines all options are conceivable. This is a case of a 27-year-old man who benefited from a new surgical approach: myotomy for MB of the left anterior descending coronary artery with the help of left robotic thoracoscopy.
Left Anterior Descending Artery Myocardial Bridging: A Clinical Approach
A myocardial bridge (MB) is the term for the muscle overlying the intramyocardial segment of the epicardial coronary artery (referred to as a tunneled artery). Although MBs can be found in any epicardial artery, most of them involve the left anterior descending artery. These congenital coronary anomalies have long been recognized anatomically, and are traditionally considered a benign condition; however, the association between myocardial ischemia and MBs has increased their clinical relevance. This review summarizes the prevalence, pathophysiology, and diagnostic findings, including morphological, functional assessment, and treatment of patients with MB involving the left anterior descending artery, suggesting a pragmatic clinical approach to this entity.
Long-Term Prognosis of Patients with Myocardial Bridge and Angiographic Milking of the Left Anterior Descending Coronary Artery
Myocardial bridging with systolic compression (milking) of the left anterior descending coronary artery may be associated with myocardial ischemia. Little information is available about the long-term prognosis of patients with this coronary anomaly. Material and methods. A review was made of coronary angiographies of patients diagnosed as ischemic heart disease made between 1994 and 1999 in two centers. The long-term follow-up of patients with myocardial bridging and systolic compression of the left anterior descending coronary artery was analyzed. Data were collected by reviewing medical records and completed by telephone interview. Results. Prevalence: 0.72%. Milking was observed in 60 patients, but 25 of them were excluded due to associated hypertrophic cardiomyopathy, severe valvular disease, or coronary artery disease.
Myocardial bridging as a cause of acute myocardial infarction: a case report
Systolic compression of a coronary artery by overlying myocardial tissue is termed myocardial bridging. Myocardial bridging usually has a benign prognosis, but some cases resulting in myocardial ischemia, infarction and sudden cardiac death have been reported. We are reporting a case of myocardial bridging which was complicated with acute myocardial infarction associated with inappropriate blood donation. A 33 year-old-man was admitted to our emergency with acute anteroseptal myocardial infarction after a blood donation.
A potential protective element of myocardial bridge against severe obstructive atherosclerosis in the whole coronary system
Myocardial bridge (MB) is generally described as a congenital benign variation. Previous studies have suggested that MB prevents atherosclerotic plaques from accumulating within the bridge segment but promotes coronary stenosis in the proximal segment adjacent to MB. However, it is still not clear whether MB has positive or negative effects on severe obstructive atherosclerosis in the whole coronary artery system.
Myocardial bridging: A ‘forgotten’ cause of acute coronary syndrome – a case report
During a stress test, an asymptomatic 40-year-old man showed an ST depression above 4 mm and a horizontal ST depression above 2 mm in the V3 to V6 precordial leads during the recovery phase, without symptoms related to myocardial ischemia. After several days, he experienced recurrent episodes of oppressive retrosternal pain with radiation to the interscapular region, associated with stress dyspnea. Stress myocardial scintigraphy using technetium sestamibi was performed, which showed a modest push-pull deficit of perfusion in the septal-anterior basal area associated with a small deficit of perfusion in the apical region.
MYOCARDIAL BRIDGE AND ACUTE PLAQUE RUPTURE
A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered.
Does isolated myocardial bridge really interfere with coronary blood flow?
Myocardial bridge (MB) is defined as a segment of a major epicardial coronary artery the “tunneled artery” that goes intramurally through the myocardium beneath the muscle bridge. Multiple methods have been proposed to assess coronary flow rate among which thrombolysis in acute myocardial infarction frame count was a relatively new semiquantitative method. Myocardial bridging must be considered especially in patients at low risk for coronary atherosclerosis but with angina like chest pain or established myocardial ischemia. We suggest that coronary blood flow is decreased in the patients with MB compared with the patients having normal coronary.
EFFECT OF SURGICAL UNROOFING OF A MYOCARDIAL BRIDGE ON EXERCISE INDUCED QT INTERVAL DISPERSION AND ANGINAL SYMPTOMS IN PATIENTS WITH ANGINA IN THE ABSENCE OF OBSTRUCTIVE CORONARY ARTERY DISEASE
Prior studies have shown that exercise significantly increases the rate corrected QT dispersion (QTcd) in patients with a myocardial bridge (MB), suggesting repolarization abnormalities due to ischemia in the area perfused by the bridged artery. We studied the effect of surgical unroofing on exercise induced QTcd and anginal symptoms in patients with a symptomatic MB. In patients with a hemodynamically significant MB who fail medical management, surgical unroofing reduces exercise induced QTcd and significantly improves anginal symptoms, presumably by relieving the ischemia caused by the bridged artery.