Anomalous Right Coronary Artery Origin from Left Main Stem: Role of Cardio-Computed Tomography in the Diagnosis and Therapeutic Approach.

Anomalous coronary arteries (ACAs) are rare but potentially life-threatening abnormalities of coronary circulation. Most of the variants are benign; however, some may lead to myocardial ischemia and/or sudden cardiac arrest. We report the case of a 75-year-old male complaining of exertion chest discomfort. Admission electrocardiogram on presentation showed sinus bradycardia with a slight elevation of ST-T in inferior leads. Troponin levels, however, were normal. Coronary angiography showed an anomalous right coronary artery (RCA) originating from the left main stem without significant stenosis. Cardio-CT confirmed the anomalous origin of the RCA from the left main stem and showed its anomalous course between the aorta and the pulmonary artery. The patient was deemed a candidate for surgery and transferred to a cardiac surgery center. Only the exact definition of the anatomic and clinical features of ACAs may allow the identification of the most appropriate and effective treatment. Multislice computed tomography may play a fundamental role in the diagnosis and treatment of ACAs.

INTRODUCTION

Anomalous coronary arteries (ACAs) are rare but potentially life-threatening abnormalities of coronary circulation. Most of the variants are benign; however, some may lead to myocardial ischemia and/or sudden cardiac arrest.[1]

CASE REPORT

We report the case of a 75-year-old male with no relevant medical history, complaining of intermittent chest discomfort, lasting <2 min, nonradiating, resolving spontaneously or with sublingual nitroglycerin, and worsening with exertion. Admission electrocardiogram on presentation showed sinus bradycardia with slight elevation of ST-T in inferior leads. Troponin levels, however, were normal. Echocardiogram revealed a normal left ventricular ejection fraction (60%). The patient was admitted to cardiology ward for unstable angina and underwent coronary angiography that showed an anomalous right coronary artery (RCA) originating from the left main stem without significant stenosis.

Cardio-TC confirmed the anomalous origin of the RCA from the left main stem and showed its anomalous course between the aorta and the pulmonary artery [Figure 1]. The patient was deemed a candidate for surgery and transferred to a cardiac surgery center.

Figure 1

(a) Axial view of emergency of the left coronary artery. (b) Course reconstruction of the right coronary artery. (c) Course reconstruction of right coronary artery up to the posterior descending coronary artery. (d) Coronary artery passage between the aorta and pulmonary artery. (e-f) Multiplanar images of interarterial course of the right coronary artery. (g-i) Left anterior descending artery

The incidence of coronary anomalies in patients undergoing coronary angiography for suspected coronary obstructive disease varies from 0.64% to 1.6%.[2] There are many classifications of ACAs in literature, classifying such anomalies into “major” and “minor” according to their clinical relevance.[3] Anomalous origin of the RCA from the left main stem (single coronary artery) is associated with myocardial ischemia caused by the inadequate coronary circulation.[45] Moreover, the ACA subtype passing between the aorta and pulmonary artery is rare but more dangerous[6] for the possibility of coronary occlusion during systolic aortic expansion,[7] malignant arrhythmias, and sudden death. Conventional coronary angiography is the gold standard in the diagnosis of ACAs; however, it does not provide relevant information about the anatomy and course of anomalies.[8] A variety of techniques, other than conventional coronary angiography, have been used in diagnostic imaging of the coronary arteries. Multislice computed tomography (MSCT) is characterized by great reliability and reproducibility in the morphological assessment of coronary arteries.[91011] MSCT can clearly delineate the anatomy and has replaced angiography as the definitive diagnostic tool.[1213] So far, the best therapeutic option for ACAs, either conservative drug therapy, coronary angioplasty, or coronary artery bypass grafting, is still debated,[1415] given the huge heterogeneity of possible coronary anomalies and clinical presentation. However, MSCT might play an important role in identification of malignant variants of ACAs, in risk stratification, and in choosing the optimal therapeutic option.

CONCLUSION

Only the exact definition of the anatomic and clinical features of ACAs may allow the identification of the most appropriate and effective treatment. MSCT may play a fundamental role in the diagnosis and treatment of ACAs.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.