Anomalous origin of the right coronary artery with an interarterial course and intramural part.

INTRODUCTION: An anomalous origin and course of the right coronary artery (RCA)(1) is a very rare congenital anomaly that can be fatal if it remains undiscovered. PRESENTATION OF CASE: In this case report, we present a patient with a one-year history of exercise-induced angina and dyspnea caused by anomalous origin of the RCA from the left sinus, and anomalous course between the aorta and the pulmonary artery. DISCUSSION: Possible mechanisms of this disease's symptomatology are compression of the RCA between the aorta and the pulmonary artery in its anomalous inter-arterial course, and squeezing of the RCA in the proximal intramural part.
CONCLUSION: In this report, we present some unique images of the RCAs course, which contribute to the understanding of this disease's symptomatology. The patient successfully underwent surgery with Right Internal Mammary Artery to RCA (RIMA-RCA)(2) bypass with complete remission of all symptoms.

Introduction

An anomalous origin of the right coronary artery from the left sinus of Valsalva is a rare congenital anomaly found in approximately 0.1% of patients undergoing angiography [1]. The anomalous inter-arterial course in found is 99% of patients with anomalous RCA [2]. The clinical manifestations are highly variable, and the condition has been associated with sudden cardiac death, myocardial ischemia, syncope, but it is mainly clinically silent [3], [4].

Presentation of case

A 39-year-old woman with a one-year history of exercise-related angina, dyspnea, and palpitations was referred to our clinic. The patient had not experienced dizziness or syncope/near-syncope, and she had no risk factors for atherosclerosis. Echocardiography was normal but coronary angiography revealed anomalous origin of the right coronary artery, departing independently from the left coronary Sinus of Valsalva, close to the origin of the left coronary artery. The proximal part of the RCA seemed to be coursing intramurally in the aortic vessel wall before running between the aorta and pulmonary artery (Fig. 1, Fig. 2). A positive ischemia test was performed on an ergometer bicycle and Positron Emissions Tomography–Computed Tomography (PET–CT)3 showed stress-induced ischemia of the myocardium supplied by the RCA.

Fig. 1

Computer tomography showing the origin of the RCA. The RCA departing from the left coronary sinus close to the pulmonary artery with a course anteriorly to aorta. Normal morphology of the left coronary artery.

Fig. 2

3D reconstruction of a Computed Tomography image showing an anomalous origin and course of the RCA.

A RIMA–RCA bypass was made with no complications and the patient was discharged 4 days later. At the 6-week follow-up the patient’s symptoms had subsided completely.

Discussion

As described, coronary anomalies have been associated with a wide range of cardiac symptoms; however, the mechanisms behind the symptoms are poorly understood. Pinching of the anomalous RCA between the aorta and the pulmonary artery caused by the increased cardiac output during exercise has been proposed [5]. Also, an intussusception of the initial part of the RCA in the aortic wall, resulting in an intramural part, may make it vulnerable for compression by the expanding aorta on increased cardiac output [3].

Up to one-third of sudden cardiac deaths in the young population are caused by coronary anomalies, and especially an intramural and inter-arterial course, as suspected in this case, is associated with the severe symptoms [6], [7]. An early diagnosis is crucial [8].

This case report describes a rare condition with a potential fatal outcome, and thereby underlines the importance of early awareness of the condition. Also, it is absolute essential to optimize the image information about the aorta annulus anatomy with individualized projections. In this case we analyzed the images using ‘Toshiba Aquilion One’ software, and were moreover, we are able to present unique images of the RCAs entire course demonstrating its vulnerability between the aorta and the pulmonary artery. Different management strategies have been used, but recently the primary strategy has shifted from medical observation to surgical treatment, however still depending on the symptoms [9]. Among the surgical techniques used are the bypass graft surgery, reimplantation of the coronary ostium, unroofing technique, and direct translocation of the pulmonary artery [10]. Some of these symptoms and management strategies from other case series have been highlighted in Table 1.

Table 1

Key case series.

Paper	Coronary artery anomaly	Inter-arterial course	Intramural part	Symptoms	Management strategy
[11]	The left coronary artery originating from the right sinus of Valsalva	Yes	No	Exercise-inducedsyncope	Creation of a neo-ostium in the left coronary sinus, and patch angioplasty using pulmonary arterial wall tissue
[12]	The right coronary artery originating from the left sinus of Valsalva	Yes	No	Chest pain	Surgical approach using the right gastroepiploic artery as coronary bypass graft
[13]	The left coronary artery originating from the right sinus of Valsalva	Yes	No	Exercised-induced chest pain and presyncopal symptoms	Increase of the distance between the main pulmonary artery and the aorta by mobilization of the pulmonic root and pulmonary bifurcation
[14]	The right coronary artery originating from the left sinus of Valsalva	Yes	Yes	Chest pain and dyspnea on exertion	Stenting of the proximal intramural part of the RCA using percutaneous coronary intervention
[15]	The right coronary artery originating from the left sinus of Valsalva	Yes	No	Exercise-induced chest pain and dyspnea	Beating heart coronary ostial translocation with an anastomosis assist device

Conflict of interest

No conflicts to declare.

Funding

No funding was received for this study.

Ethical approval

The study was exempt from formal approval by The Regional Committee on Biomedical Research Ethics of the Central Denmark Region.

Consent

Informed consent was obtained from the patient for publication of this case report and accompanying images.

Authors contribution

All authors have taken part in conception and interpretation of data, drafting or revising the manuscript critically, and final approval of the manuscript submitted.

Guarantor

Simon Fuglsang.