Usefulness of MRI to demonstrate the mechanisms of myocardial ischemia in hypertrophic cardiomyopathy with myocardial bridge

"Under the Bridge": Looking for Ischemia in a Patient with Intramyocardial Coronary Artery Course-The Role of the Cardiopulmonary Exercise Test

Many variables obtained during cardiopulmonary exercise test (CPET), including O2 uptake (VO2) versus heart rate (HR, O2-pulse) and work rate (VO2/Watt), provide quantitative patterns of responses to exercise when left ventricular dysfunction is an effect of myocardial ischemia (MI). Therefore, CPET offers a unique approach to evaluate exercise-induced MI in the presence of fixed or dynamic coronary arteries stenosis. In this paper, we examined the case of a 74-year-old patient presenting with an ischemic CPET and a normal stress cardiac magnetic resonance (CMR) with dipyridamole. A coronary angiography demonstrated the presence of myocardial bridging (MB), a well-known congenital coronary anomaly that is able to generate MI during exercise (but not in provocative testing using coronary artery vasodilators, such as dipyridamole). Despite the good diagnostic accuracy of the imaging methods (i.e., stress CMR) in MI detection, this case shows that exercise should be the method of choice in elicit ischemia in specific cases, like MB.

A Comprehensive Review of Myocardial Bridging: Exploring Diagnostic and Treatment Modalities

Myocardial bridging (MB) is a congenital coronary artery anomaly involving an overlying myocardium's partial or complete encasement of a coronary artery segment. The obstruction can lead to significant cardiac symptoms, resulting in myocardial ischemia, arrhythmia, and sudden cardiac death. Several approaches, including invasive and non-invasive methods, have been proposed to diagnose and manage MB. Invasive modalities, such as intravascular ultrasound (IVUS) and coronary angiography, offer high specificity and sensitivity. In contrast, non-invasive methods like Doppler ultrasound, multislice computed tomography (MSCT), and magnetic resonance imaging (MRI) are advantageous due to their non-invasive nature, high sensitivity and specificity, and cost-effectiveness. Treatment options for MB mainly focus on relieving symptoms and preventing adverse outcomes. The use of pharmacological agents and surgical and percutaneous interventions has been documented in numerous studies. Studies conclude that MB is a treatable cardiac anomaly, and a combined approach of diagnosis, treatment, and follow-up is necessary to reduce the morbidity and mortality associated with this condition.

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.

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.

Incidence and clinical significance of myocardial bridging with ECG-gated 16-row MDCT coronary angiography

AIMS

The aims of this study were to evaluate the incidence and the clinical significance of myocardial bridging in 401 patients with chest pain examined with 16-row Multidetector CT (MDCT) coronary angiography.

MATERIAL AND METHODS

Four hundred nine consecutive patients who had chest pain or symptoms suggestive of coronary artery disease were involved in this study. Patients with heart rates >or=65 beats/min received 25-50 mg of atenolol orally 1 h before the scan. CT coronary angiography was performed with a 16-row MDCT scanner. CT coronary angiographic images were evaluated by consensus of two radiologists, who were blinded to clinical information. Clinical correlation was made between the presence and type of myocardial bridging on MDCT and the clinical results based on history, examination, and any subsequent clinical workup at the 2-month follow-up by a consensus of two physicians.

RESULTS

Among the 401 patients, 23 (5.7%) cases of myocardial bridging were detected. Twenty-one (5.2%) cases of myocardial bridging were located at the middle third of the left anterior descending coronary artery (LAD), one (0.25%) case was at the proximal third of the LAD, and one (0.25%) case was at the distal third of the LAD. Superficial bridging was identified in 15 patients and deep bridging in 8. The length of tunneled artery was between 5 and 27 mm, with a mean of 15.7 mm, and the depth of tunneled artery was between 1.0 and 7.0 mm, with a mean of 3.2 mm. Out of four patients whose chest pain was assumed to be associated with myocardial bridging, three patients had deep bridging. In the other 19 patients with bridging, alternative causes of chest pain were present.

CONCLUSIONS

We found the incidence of myocardial bridging in this patient group to be 5.7%. Larger multicenter studies are required to evaluate the incidence of myocardial bridging and to determine a link between myocardial bridging and chest pain.