Origin of the left anterior descending coronary artery from the right aortic sinus with intramyocardial tunneling to the left side of the heart via the ventricular septum: a case against clinical and morphologic significance of myocardial bridging

Myocardial bridge and beta blockers: effect on left ventricular strain parameters

OBJECTIVES

To assess the effect of beta-blocker treatment on left ventricular global longitudinal strain (LV Gls) as measured by echocardiography in patients with MB (Myocardial Bridge).

PATIENTS AND METHODS

Between January 2019 and February 2022, a prospective, single-center study was undertaken in which myocardial bridging was identified in individuals who had coronary angiography. One hundred patients with myocardial bridging were systematically recruited and strain echocardiography was performed. Patient data were analysed in two groups - those who weren't using beta-blockers in the last six months (Group I: n = 50) vs. those who were (Group II: n = 50).

RESULTS

One hundred patients participated in the study (38 females, 62 males; average age: 57.4 years). There was a statistically significant difference in the mean heart rate between groups I and II (p < 0.001). LV Gls was found to be statistically significantly improved in favour of group II when compared to group I [Group I: (-12.57)±3 vs. Group II: (-15.92)±2.9, p < 0.001].

CONCLUSION

The negative chronotropic effect of beta-blocker medication in individuals with MB identified by coronary angiography has a beneficial effect on LV Gls as measured by echocardiography.

Myocardial Ischemia in Children With Anomalous Aortic Origin of a Coronary Artery With Intraseptal Course

Background:

Intraseptal anomalous aortic origin of a coronary artery is considered a benign condition. However, there have been case reports of patients with myocardial ischemia, arrhythmia, and sudden cardiac death. The purpose of this study was to determine the clinical presentation, myocardial perfusion on provocative stress testing, and management of children with anomalous aortic origin of a coronary artery with an intraseptal course in a prospective cohort.

Methods:

Patients with anomalous aortic origin of a coronary artery and intraseptal course were prospectively enrolled from December 2012 to May 2019, evaluated, and managed following a standardized algorithm. Myocardial perfusion was assessed using stress imaging. Fractional flow reserve was performed in patients with myocardial hypoperfusion on noninvasive testing. Exercise restriction, β-blockers, and surgical intervention were discussed with the families.

Results:

Eighteen patients (female 6, 33.3%), who presented with no symptoms (10, 55.6%), nonexertional (4, 22.2%), and exertional symptoms (4, 22.2%), were enrolled at a median age of 12.4 years (0.3–15.9). Perfusion imaging was performed in 14/18 (77.8%) and was abnormal in 7/14 (50%); fractional flow reserve was positive in 5/8 (62.5%). All 4 patients with exertional symptoms and 3/10 (30%) with no or nonexertional symptoms had myocardial hypoperfusion. Coronary artery bypass grafting was performed in a 4-year-old patient; β-blocker and exercise restriction were recommended in 4 patients not suitable for surgery. One patient had nonexertional chest pain and 17 were symptom-free at median follow-up of 2.5 years (0.2–7.1).

Conclusions:

Up to 50% of patients with intraseptal anomalous aortic origin of a coronary artery had inducible myocardial hypoperfusion during noninvasive provocative testing. Long-term follow-up is necessary to understand the natural history of this rare anomaly.

Perfusion Study Helps in the Management of the Intraseptal Course of an Anomalous Coronary Artery

Anomalous origin of a coronary artery from the opposite aortic sinus of Valsalva can present in various ways, ranging from a benign and incidental finding to sudden cardiac death. The variant with an intraseptal subpulmonary course (sometimes referred to as intraconal), is widely perceived to carry a low risk of ischemia and has been considered to be a benign variant, not requiring surgical treatment. In one of our recent patients, however, nuclear scintigraphy highlighted a myocardial perfusion deficit in the territory supplied by the allegedly benign anomalous coronary artery, prompting the need for a more aggressive surgical approach.

Transseptal course of anomalous left main coronary artery originating from single right coronary orifice presenting as unstable angina

Transseptal course of coronary artery has often been described as a benign entity; however, this report and literature analysis provides growing evidence of high risk of serious cardiovascular events in this anomaly. We present a case of unstable angina in a patient with anomalous common origin of left and right coronary arteries from a single coronary ostium at the right sinus of Valsalva, with subsequent transseptal course of the left main artery, review of relevant literature, and discussion of possible management options.

Cardiac MRI and CT: differentiation of normal ostium and intraseptal course from slitlike ostium and interarterial course in anomalous left coronary artery in children

OBJECTIVE

Anomalous left coronary artery from the inappropriate aortic sinus with intraseptal course is generally benign but can be confused on imaging studies with the potentially lethal interarterial, intramural anomalous left coronary artery. The purpose of this study was to assess normal ostial morphologic features and intraseptal course using cardiac MRI and CT in pediatric patients with intraseptal anomalous left coronary artery.

MATERIALS AND METHODS

A retrospective review was conducted of the medical records of 14 children with the diagnosis of intraseptal anomalous left coronary artery between November 2009 and March 2013. Coronary artery origin and course were evaluated with cardiac MRI or CT, and 3D assessment of coronary ostial morphologic features was performed with virtual angioscopy.

RESULTS

The patient ages ranged from 5 to 18 years at diagnosis; 10 (71.4%) were boys. The right and left coronary origins were the right sinus of Valsalva as a common origin (n = 9) or a single coronary artery (n = 5). Anomalous intraseptal left main coronary was found in 13 patients, and one patient had anomalous left anterior descending with retroaortic circumflex coronary artery. Anomalous coronary ostia were round and without stenosis in all studies. The anomalous vessel was identified with echocardiography, but the anomalous left coronary artery was not delineated, and a normal ostium was not adequately portrayed in any instance.

CONCLUSION

By use of cardiac MRI and CT, the anomalous course of round coronary ostia was confirmed and visualized in a pediatric cohort with intraseptal anomalous left coronary artery. The data provide the basis for understanding the benign clinical course and showing that surgery is unnecessary for this coronary anomaly.

[Long-term prognosis of patients with myocardial bridge and angiographic milking of the left anterior descending coronary artery]

INTRODUCTION

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. The clinical follow-up was available for all patients (median: 43 months, range: 12-80 months). Mean age 55.7 years (SD = 11.9). Men 74%.

CLINICAL PRESENTATION

angina 26 patients, atypical chest pain with positive non-invasive test 8, acute myocardial infarction 1. During follow-up, 1 patient died of sudden cardiac death. Seven patients continued to present stable angina CCS class I-II, coronary angiography was repeated in 5 patients, and one required percutaneous revascularization for symptoms. In 63% of cases, antianginal drugs were still needed at the end of follow-up period (beta-blockers or calcium antagonists).

CONCLUSIONS

Patients with myocardial bridging and systolic compression of the left anterior descending artery have a good long-term prognosis, although more than half of them continue regular treatment with antianginal drugs. In a small percentage of cases percutaneous intervention must be performed and ischemic heart disease may appear in more aggressive forms (acute myocardial infarction or sudden death).

Unusual congenital coronary anomaly and myocardial ischaemia

Angiography was used to diagnose a rare congenital coronary anomaly with myocardial ischaemia in a woman with typical angina. All three coronary arteries arose from a solitary coronary ostium in the right aortic sinus; the left anterior descending coronary artery followed a septal course, the circumflex coronary artery ran behind the ascending aorta, and the right coronary artery followed a normal course. No significant coronary lumen narrowing was found. Transoesophageal echocardiography confirmed the anomalous origin and course of the aberrant coronary arteries. An exercise test reproduced angina, and ECG changes and myocardial perfusion study showed an anterior reversible defect. In contrast to previous reports, myocardial ischaemia was associated with the septal (intramuscular) course of the left anterior descending coronary artery; there was no other significant coronary artery disease.

Chronic degenerative changes in the myocardium supplied by bridged coronary arteries in eight postmortem samples

In humans, the coronary arteries course not only subepicardially but also intramyocardially. The intramyocardial course of the coronary artery is reported to lead to acute ischemic heart disease and, as well, it may be symptomless. The aim of this study was to investigate the long-term ischemic effects of bridged arteries on the myocardium, and was carried out on 8 autopsy hearts with myocardial bridges and 2 hearts without myocardial bridges. The samples from the myocardium were examined with light microscopy. In the myocardium supplied by the bridged arteries, it was observed that there was an increase in the intercellular connective tissue, which was rich in collagen bundles, lymphocytes, fibroblasts and macrophages. Compression of the coronary artery by myocardial bridges may cause chronic degenerative changes, which may remain silent for a long time.

Nonatherosclerotic causes of coronary artery narrowing--Part II

Part II of this three-part article on nonatherosclerotic causes of coronary heart disease focuses on myocardial bridges, coronary artery aneurysms, emboli, coronary dissection, and spasm as causes of luminal narrowing.

Functional, angiographic and intracoronary Doppler flow characteristics in symptomatic patients with myocardial bridging: effect of short-term intravenous beta-blocker medication

OBJECTIVES

We sought to define the effects of short-term beta-adrenergic blocking medication on intracoronary flow characteristics, clinical symptoms and angiographic diameter changes in patients with severe myocardial bridging of the left anterior descending coronary artery.

BACKGROUND

Controversy exists regarding the pathophysiology, clinical relevance and optimal therapy in symptomatic patients with myocardial bridges because antianginal drugs have not been systematically tested.

METHODS

In 15 symptomatic patients with myocardial bridging of the left anterior descending coronary artery, maximal lumen diameter reductions were evaluated by quantitative coronary angiography. There were no angiographic signs of coronary artery disease. Coronary blood flow velocities (using a 0.014-in. [0.035 cm] Doppler guide wire) were measured at rest, during atrial pacing and during intravenous administration of a short-acting beta-blocker (esmolol, 50 to 500 micrograms/kg body weight per min) with continuous atrial pacing.

RESULTS

The maximal angiographic systolic lumen diameter reduction within the myocardial bridges was 83 +/- 9% at rest, with a persistent diastolic diameter reduction of 41 +/- 11% (mean +/- SD). Short-term intravenous beta-blocker therapy decreased the diameter reduction during both systole (from 83 +/- 9% to 62 +/- 11%) and diastole (from 41 +/- 11% to 30 +/- 9%, both p < 0.001). The average diastolic peak flow velocity was higher within the myocardial bridges (33 +/- 13 cm/s) than the proximal (26 +/- 13 cm/s) and distal bridges (17 +/- 4 cm/s, both p < 0.001). During tachypacing, average diastolic peak flow velocity increased within the bridged segments to 63 +/- 21 cm/s versus 29 +/- 12 cm/s in the proximal and 20 +/- 4 cm/s in the distal bridges (both p < 0.001). Beta-receptor blockade produced a return to baseline values (average diastolic peak flow velocity within bridge 35 +/- 16 cm/s, p < 0.001). ST segment changes and symptoms were abolished with beta-blocker administration.

CONCLUSIONS

In patients with myocardial bridges, administration of short-acting beta-blockers during atrial pacing alleviates anginal symptoms and signs of ischemia. This effect was mediated by a reduction of vascular compression and maximal flow velocities within the bridged coronary artery segment.

Anatomy, histology, and pathology of coronary arteries: a review relevant to new interventional and imaging techniques--Part IV

In the last 15 years, intense interest has focused on various interventional pharmacologic and mechanical forms of therapy for the treatment of atherosclerosis coronary artery disease. Many techniques and devices (dilating balloons, perfusion catheters, thermal probes and balloons, lasers, atherectomy devices, stents, intravascular ultrasound) have been used or are under study for future use. Many of these techniques and devices require an understanding of histologic and pathologic features of the coronary arteries and diseases which affect them. This article reviews selective areas of anatomy, histology, and pathology relevant to the use of various new interventional techniques. Part IV of this review will focus on congenital coronary artery anomalies, myocardial bridges, coronary aneurysm, emboli, and dissection and clinical implications regarding echocardiographic imaging techniques.

Anatomy, histology, and pathology of coronary arteries: a review relevant to new interventional and imaging techniques--Part I

In the last 15 years, intense interest has focused on various interventional pharmacologic and mechanical forms of therapy for the treatment of atherosclerosis coronary artery disease. Many techniques and devices (dilating balloons, perfusion catheters, thermal probes and balloons, lasers, atherectomy devices, stents, intravascular ultrasound) have been used or are under study for future use. Many of these techniques and devices require an understanding of histologic and pathologic features of the coronary arteries and diseases which affect them. This article reviews selective areas of anatomy, histology, and pathology relevant to the use of various new interventional techniques. Part I of this review will focus on anatomic aspects of the epicardial coronary artery system, coronary arterial distribution, myocardial supply, and histologic features of the normal coronary artery.

External compression by metastatic squamous cell carcinoma: a rare cause of left main coronary artery narrowing

A 69-year-old male with carcinoma of the lung developed unstable angina pectoris during his last few months of life. At necropsy, the coronary arteries were free of atherosclerotic plaque, but the left main artery was severely narrowed by external compression from neoplastic metastases. Persistent anterior ST-segment elevation without evolutionary changes of myocardial infarction was a clue to cardiac involvement by tumor. Direct and indirect effects of metastatic tumors upon the coronary arteries include tumor or thrombi, emboli, wall invasion, or extrinsic wall compression. Extrinsic compression of the left main coronary artery is rare among congenital and acquired conditions producing severe left main disease.

Anatomy, histology, and pathology of the major epicardial coronary arteries relevant to echocardiographic imaging techniques

We are at the threshold of a new era of coronary artery imaging with the use of transthoracic, transesophageal, and intravascular ultrasound. Echocardiographic imaging has the capability of assessing changes of the lumen and walls of major epicardial coronary arteries. This article reviews certain anatomic, histologic, and pathologic observations of the major epicardial coronary arteries relevant to these various echocardiographic imaging techniques.

Normal and anomalous coronary arteries: definitions and classification

Results of a comprehensive survey of the literature concerning coronary artery anatomy, embryology, and pathophysiology show the lack of an adequate definition of normal coronary arteries. To fill this gap, the present review considers the available data concerning the embryogenesis of the coronary arteries and proposes a new definition of normality that refers to essential anatomic features. The concepts of normal variant versus anomaly are introduced, based on a statistical definition of the normal range (99% of the presentations observed in a normal, unselected population). Coronary anomalies are defined as those patterns found in less than 1% of the cases. The wide spectrum of coronary abnormalities is then organized according to a comprehensive classification scheme. For clinical purposes the conceptual difference between anatomic and pathophysiologic anomalies is stressed. The current paucity of experimental studies concerning normal and abnormal embryogenesis of the coronary arteries is found to be the major limitation to an understanding of this subject.