Myocardial Bridging: Diagnosis, Functional Assessment, and Management: JACC State-of-the-Art Review.

Myocardial bridging (MB) is a congenital coronary anomaly in which a segment of the epicardial coronary artery traverses through the myocardium for a portion of its length. The muscle overlying the artery is termed a myocardial bridge, and the intramyocardial segment is referred to as a tunneled artery. MB can occur in any coronary artery, although is most commonly seen in the left anterior descending artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB associated with ischemic symptomatology. The advent of contemporary functional and anatomic imaging modalities, both invasive and noninvasive, have dramatically improved our understanding of dynamic pathophysiology associated with MBs. This review provides a contemporary overview of epidemiology, pathobiology, diagnosis, functional assessment, and management of MBs.

Challenges in Evaluation and Management of Children with Myocardial Bridging.

Myocardial bridging (MB) is a congenital anomaly where a coronary artery branch or group of branches extends inside a tunnel consisting of myocardium. Although it is mostly considered "benign," it is reported that MB may lead to significant cardiac problems and sudden cardiac deaths. While it is a congenital anomaly, its symptoms usually arise at further ages rather than childhood. The literature on MB in children is in the form of case reports or small case series. This is why pediatric cases are assessed in the light of information obtained from adults. This review compiled the literature on MB in adults and children and compared it, as well as discussing questions arising regarding the clinic, diagnosis, and treatment of MB.

Case Report: Myocardial Bypass in Left Descending Artery - A Rare Congenital Anomaly

Abstract Myocardial bypass (MB) is known to have scientific relevance and is present in several studies with great statistical significance regarding its clinical manifestations and complications. There are still questions about MB in its relationship with heart disease and repercussion in life-threatening conditions. We present a case report of a MB in the left anterior descending coronary artery, whose objective is to identify this rare congenital anomaly and to highlight the patient's clinical outcome in order to elicit greater contributions about the presence of this variant in the emergency room, its diagnosis by angiography and therapeutic management.

Recurrent attack of acute myocardial infarction complicated with ventricular fibrillation due to coronary vasospasm within a myocardial bridge: a case report.

BACKGROUND: Myocardial bridge (MB) often an inoffensive condition that goes in one or more of the coronary arteries through the heart muscle instead of lying on its surface. MBs sometimes leads to myocardial ischemic symptoms such as chest pain, even an occurrence of myocardial infarction. However, reports of severe and recurrent cardiac adverse events related to the MBs are rare. CASE PRESENTATION: A 44-year-old male patient who suffered from a four-hour crushing chest pain ten years ago, was diagnosed as acute anterior ST-elevation myocardial infarction (STEMI). The initial findings of coronary angiography (CAG) showed MB was located in the middle part of the left anterior descending coronary artery (LAD). The patient was managed medically. Another re-attack of similar previous chest pain characteristics occured just after 3 days of discharge. Supra-arterial myotomy and CABG were the next adopted management. Postoperative progression was uneventful. However, 32 months after surgical treatment, the patient experienced an abrupt onset of chest pain accompanied by loss of consciousness. The ECG showed ventricular fibrillation (VF). After electrical cardioversion, an immediate CAG followed by CTA was performed which excluded thrombus or acute occlusion in the native coronary artery and an occlusion was observed at the end of the left internal mammary artery. An implantable cardioverter-defibrillator (ICD) was successfully performed for prevention of malignant arrhythmia. During ten years of follow-up, no complications have been identified. CONCLUSIONS: Although MB is mostly benign, it may lead to significant cardiovascular consequences. Supra-arterial myotomy is an appropriate treatment option for this patient who failed to optimal medical therapy. Furthermore, ICD implantation must be considered in order to prevent malignant ventricular arrhythmia caused by continuous spasm resulting in ischemia. Further investigations are required to confirm the clinical effectiveness of these procedures.

Wearable cardioverter-defibrillator as bridging to ICD in pediatric hypertrophic cardiomyopathy with myocardial bridging - a case report.

BACKGROUND: There is only limited experience with wearable cardioverter-defibrillators (WCD) in pediatric patients. We report on the successful application of a WCD in an adolescent patient with hypertrophic cardiomyopathy and myocardial bridging. CASE PRESENTATION: A 15-year-old girl presented with a history of recurrent syncope, dyspnea, and vertigo with exercise. Diagnostic work-up revealed non-obstructive hypertrophic cardiomyopathy and signs of myocardial ischemia with exercise. Given this high-risk constellation, the patient was scheduled for prophylactic implantation of an implantable cardioverter-defibrillator (ICD). One month after initial presentation and days prior to the planned ICD implantation, the patient collapsed during an episode of sustained ventricular tachycardia (VT) while running. VT was terminated by WCD shock delivery. Following this event, computerized tomography scan revealed myocardial bridging of the left anterior descending coronary artery causing a 90% stenosis in systole. After coronary surgery, life threatening arrhythmias have not recurred, but due to progressive heart failure, the patient underwent successful heart transplantation after 2 years. CONCLUSIONS: The reported case highlights the importance and applicability of WCDs and the potentially malign nature of myocardial bridging in pediatric high-risk patients.

Chest Pain During Chemotherapy: A Case of Severe Myocardial Bridging.

A cancer patient presented with acute chest pain at rest 40 hours after IV fluorouracil infusion. Angiography showed evidence of myocardial bridging.

Symptomatic myocardial bridging: a frequently occurring coronary variation can cause severe myocardial ischaemia in affected children with underlying cardiac conditions.

Myocardial bridging is a congenital coronary artery anomaly in which the coronary artery has a partly "tunnelled" intramyocardial course. This tunnelling leads to compression of the affected vessel segment during ventricular systole. It is considered to be a benign variation of the norm in about 25% of the population caused by an aberrancy of embryologic coronary development. The bridging is also thought to cause severe cardiac conditions in a few of those affected. The series of six young patients presented here is the largest series so far to report on symptomatic myocardial bridging in children with different underlying heart diseases. All patients recently presented to our centre with signs of myocardial ischaemia. They subsequently underwent coronary angiography, which revealed myocardial bridging of the ramus interventricularis anterior. In all patients, therapy with ß blockers was started to reduce heart rate and myocardial contractility. ß Blocker treatment was also given in order to prolong diastole and improve coronary artery blood flow. Two patients underwent surgical exposure of the involved coronary segment: a 2-year-old boy because of recurrent, severe myocardial ischaemia in combination with a reduction of general health, changes in ST-segments, and the presence of a dilative cardiomyopathy; and a 13-year-old girl because of evidence of myocardial ischaemia during exercise testing after surviving sudden cardiac death. Surgery was successful and recovery was complete and uneventful. The presented series shows that myocardial bridging can be symptomatic and may require urgent treatment and even surgical intervention in early childhood in rare cases.

[Myocardial bridge as the only cause of acute coronary syndrome among the young patients].

OBJECTIVE: Introduction: Myocardial bridge is an inborn anomaly of coronary artery development, when a part of it is submerged in a myocard, which is pressing the coronary artery to a systola and restrains coronary blood circulation. Generally this feature of coronary blood circulation does not cause any clinical symptoms because the 85% of coronary blood stream of the left ventricle is provided by diastolic filling. Hemodynamic changes in atherosclerosis, tahicardie, hypertrophie of myocard are leading to the manifestation of clinical symptoms of ischemia. The aim: The purpose of the investigation was to discover the features of clinical development of acute coronary syndrome caused by myocardial bridge of young patients without the features of atherosclerotical harm of coronary arteries. PATIENTS AND METHODS: Materials and methods: Eight causes of acute coronary syndrome among patients of 28±8,5 years with myocardial bridge which was revealed during coronary angiography, were investigated. Standardized examination and conservative treatment of patients was held, except for three who have got interventional therapy. RESULTS: Results: According to our investigation, myocardial bridge of all investigated patients was located in the middle of the third front interventricular branch of the left coronary artery. Causes of acute coronary syndrome manifestation were tahicardia, spasms of coronary artery, inducted by iatrogenic factors hypertrophie of myocard, hypertrophic cardiomyopatie. Connection between the manifestation of clinical symptoms and length of tunneled segment which did not depend on the level of systolic compres was discovered. The results of conservative and interventional treatment were analyzed. CONCLUSION: Conclusions: Myocardial bridge can be the cause of myocardial ischemia among patients without signs of coronary atherosclerosis with additional hemodynamic risk facts such as tahicardia, spasms of coronary artery, hypertrophie of myocard. Clinical symptomatology of the acute coronary syndrome is more often observed among patients who's myocsrdial bridge is located in the middle of the third front interventricular branch of the left coronary artery. This is caused by perpendicular location of muscle fibers to coronary artery that increases systolic compression. Diastolic function and blood filling of coronary artery can be improved due to the medication beta-blockers therapy of patients with symptomatic myocardial bridge. A higher risk of appearance of restenosis of the stent is possible due to interventional treatment of young patients with myocardial bridge without atherosclerosis of coronary arteries.

The impact of myocardial bridge on coronary artery spasm and long-term clinical outcomes in patients without significant atherosclerotic stenosis.

BACKGROUND AND AIMS: Myocardial bridge (MB) and coronary artery spasm (CAS) can induce a sustained chest pain, acute coronary syndrome (ACS) and even sudden cardiac death. The aim of this study is to evaluate the relationship between MB and CAS and its impact on long-term clinical outcomes. METHODS: A total of 812 patients with MB without significant coronary artery disease (CAD), who underwent acetylcholine (ACH) provocation test, were enrolled. Significant CAS was defined as ≥70% temporary narrowing by ACH test, and MB was defined as the characteristic phasic systolic compression of the coronary artery with a decrease of more than 30% in diameter on the angiogram after intracoronary nitroglycerin infusion. To adjust baseline confounders, logistic regression analysis was performed. The primary endpoint was incidence of CAS, and secondary endpoints were major adverse cardiac events (MACE) and recurrent angina requiring repeat coronary angiography (CAG) at 5 years. RESULTS: MB is closely implicated in a high incidence of CAS, spontaneous spasm, ischemic ECG change and chest pain during ACH provocation test. In addition, MB of various severity and reference vessel size was substantially implicated in CAS incidence, and severe MB was a strong risk factor of CAS. MB patients with CAS were shown to have a higher rate of recurrent angina compared with MB patients without CAS, up to a 5-year follow-up. However, there were no differences regarding the incidence of MACE. CONCLUSIONS: Severe MB was associated with high incidence of CAS, and MB patients with CAS were likely to have a higher incidence of recurrent angina. Intensive medical therapy and close clinical follow-up are needed for better clinical outcomes in MB patients with CAS.

What is the optimal treatment for symptomatic patients with isolated coronary myocardial bridge? A systematic review and pooled analysis.

BACKGROUND: Myocardial bridging is a common coronary anomaly, with few severe adverse events but a relevant symptom burden. Myocardial bridging treatment, however, remains uncertain because of the lack of randomized trials. MATERIAL: MEDLINE/PubMed was systematically screened for studies reporting on isolated myocardial bridging diagnosed at coronary angiography or with coronary computed tomography in patients admitted for suspected angina or with an acute coronary syndrome. Baseline, treatment and outcome data were appraised and pooled according to treatment (medical therapy, bypass surgery/myotomy or stenting). RESULTS: A total of 899 patients in 18 studies were included with a low prevalence of traditional risk factors, especially diabetes (15.6%, interquartile range 2.5-21.5). After a median of 31.0 months (interquartile range 12.4-37.1), major cardiovascular events (composite of death, myocardial infarction or target vessel revascularization) occurred in only 3.4% of the study patients and 78.7% [70.5-86.9; 95% confidence intervals (CI)] were managed conservatively and free of symptoms. When an invasive strategy was planned, freedom from angina was higher in patients treated with surgery [84.5% (78.4-90.7; 95% CI)] than in those treated with stenting [54.7% (38.9-70.6; 95% CI)]. Patients in the stenting group experienced a high incidence of major cardiovascular events related to target vessel revascularization [40.07% (19.83-60.32; 95% CI)]. Meta-regression showed that patients treated with beta-blockers or with a history of hypertension were more likely to remain free from angina (B -0.6, P = 0.013; B -0.66, P = 0.006). CONCLUSION: Patients with symptomatic isolated myocardial bridging generally have a good long-term prognosis. Pharmacological treatment alone, especially with beta-blockers, is able to improve angina in most cases. Surgical treatment appears to be more effective than stenting in nonresponders.

Anomalous Coronary Arteries and Myocardial Bridges: Risk Stratification in Children Using Novel Cardiac Catheterization Techniques.

The evaluation of the vast majority of children with anomalous aortic origin of a coronary artery (AAOCA) and/or myocardial bridges is performed with non-invasive testing. However, a subset of these patients may benefit from invasive testing for risk stratification. All patients included in the Coronary Anomalies Program (CAP) at Texas Children's Hospital who underwent cardiac catheterization were included. Techniques included selective coronary angiograms (SCA), intravascular ultrasound (IVUS), and fractional flow reserve (FFR) measurements with provocative testing using adenosine and/or dobutamine infusions. Out of the 131 patients followed by the CAP between 12/12-4/16, 8 (6%) patients underwent 9 cath investigations at median age 13.1 (2.6-18.7) years and median weight 49.5 (11.4-142.7) kg. Six patients presented with cardiac signs/symptoms. Four patients had myocardial bridges of the left anterior descending (LAD) coronary artery, 2 patients had isolated AAOCA, and 2 patients had an anomalous left coronary artery (LCA) with an intramyocardial course of the LAD. SCA was performed in all patients. FFR was positive in 4/6 patients: IVUS showed >70% intraluminal narrowing in 3/5 patients. One patient had hemodynamic instability that reversed with catheter removal from the coronary ostium. Based on the catheterization data obtained, findings were reassuring in three patients, surgery was performed in three patients, and two patients are being medically managed/restricted from competitive sports. In our small cohort of patients, we demonstrated that IVUS and FFR can safely be performed in children and may help to risk stratify some patients with AAOCA and myocardial bridges.

Forty Years of Chest Pain: A Case Report and Contemporary Review of the Diagnostic and Therapeutic Options for Myocardial Bridging.

A 48-year-old woman with 40 years of intermittent squeezing chest pain presented with worsening symptoms. Results of an ambulatory electrocardiogram, echocardiogram, and exercise treadmill were unremarkable. Persistent symptoms prompted a computed tomography coronary angiogram (CTCA) that revealed mid-left anterior descending artery myocardial bridging (MB) that was not physiologically significant by exercise single-photon emission CT. Conservative treatment was pursued. Anatomic MB is prevalent in a large proportion of the general population and are increasingly identified by CTCA. The majority are benign, physiologically significant bridging is uncommon, but accelerated proximal atherosclerosis can occur. b-blockers and nondihydropyridine calcium-channel blockers are the primary treatment options, with surgical myomectomy, coronary artery bypass, and stenting reserved for patients refractory to medical therapy with demonstrable ischemia. Head-to-head evaluation of nonpharmacologic therapies is needed. Intracoronary techniques provide simultaneous anatomical and physiological assessment but CTCA fractional flow reserve and hybrid positron emission tomography with concomitant spatial imaging systems are evolving as noninvasive alternatives.

Coronary spasm and myocardial bridging: an elusive pathophysiological mechanism leading to apical ballooning syndrome?

Apical ballooning syndrome or Takotsubo-like cardiomyopathy is an acute syndrome characterized by normal or near-normal coronary arteries, regional wall motion abnormalities that extend beyond a single coronary vascular bed and, often, a precipitating stressor. We observed a case of an elderly lady with Takotsubo-like left ventricular dysfunction in whom both left anterior descending artery and diagonal branch coronary artery reversible spasm and myocardial bridging were demonstrated at the time of acute cardiac catheterization. It is a common observation that a combination of multiple pathophysiological mechanisms may produce a clinically similar picture. We believe that reversible, yet extreme, spasticity elicited at the level of myocardial bridging and involving a territory beyond a single coronary branch may explain in this case a functional phenomenon, namely the Takotsubo-shaped dysfunction of the left ventricle, which is more commonly observed in women with totally normal coronary arteries after exaggerated sympathetic stimulation.

Myocardia ischemia associated with a myocardial bridge with no significant atherosclerotic stenosis.

BACKGROUND: 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. CASE PRESENTATION: In present study, we reviewed four cases with myocardial bridge and no stenosis of coronary artery, which included acute coronary syndrome and sudden cardiac arrest. CONCLUSIONS: These cases indicated that cardiac events in patients with myocardial bridge may be associated with coronary spasm, myocardial supply/demand mismatch or cardiac arrest.

Myocardial Noncompaction Presenting With Myocardial Bridge: A Case Report.

Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown.We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium.The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable.This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies.

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.

Deferring coronary stenting for myocardial bridging by fractional flow reserve and optical coherence tomography.

Deciding how to treat acute myocardial infarction (MI) with myocardial bridge is difficult because stent fracture and early restenosis are frequently reported. We present a 50-year-old female patient with acute MI and myocardial bridge. Optical coherence tomography (OCT) and fractional flow reserve were used to reach a decision on treatment.