Anomalous Right Coronary Artery Originating from Left Circumflex Artery: An Unusual Single Coronary Artery Anomaly

Abstract

Isolated single coronary artery with origin of the right coronary artery from the left circumflex artery is a rare coronary artery anomaly. This particular coronary artery anomaly can be associated with myocardial ischemia and increased risk for sudden cardiac death, particularly if the anomalous artery traverses within the aortic wall or between the aorta and pulmonary artery. We present a classic example of an isolated single coronary artery with origin of the right coronary artery from the left circumflex artery found on coronary angiography prior to mitral valve repair surgery. The course of the anomalous right coronary artery was benign in this case and the patient underwent successful mitral valve repair with uneventful recovery.

Introduction

Isolated single coronary artery with origin of the right coronary artery (RCA) from the left circumflex artery (LCX) is a rare coronary artery anomaly. Depending on the course of the RCA, this finding may be benign or may place the patient at increased cardiac risk. We present a classic example of an isolated single coronary artery with origin of the RCA from the LCX found on coronary angiography prior to mitral valve repair surgery.

Case report

A 53-year-old female with a history of class III congestive heart failure (CHF) with severe mitral regurgitation (MR) and bilateral mitral leaflet prolapse underwent pre-operative coronary angiography before mitral valve repair. Coronary angiography revealed a single coronary artery with an anomalous right coronary artery originating from the left circumflex artery (Figures 1-3). The course of the anomalous right coronary artery was benign in this case and the patient underwent successful mitral valve repair with uneventful recovery.

Discussion

Isolated single coronary artery is a rare coronary artery anomaly with a described incidence of 0.024%-0.066%.^1,2 Single coronary artery with origin of the right coronary artery from the left circumflex artery has been reported to have an incidence of 0-0.035%.^1,3,4 A previous classification has called this a Lipton L1 type of anomaly.¹ Yamanaka et al found that the L1 group of single coronary artery anomalies usually has a benign clinical course.⁵ However, depending on the course of the right coronary artery, the patient with an L1 type of anomaly may be at increased risk for sudden cardiac death. In cases in which the anomalous artery traverses within the aortic wall (intramural course) or between the aorta and pulmonary artery (interarterial course), intussusception of the ectopic proximal vessel can occur and can cause myocardial ischemia due to coronary hypoplasia, lateral compression, and stenosis along the segment length.⁶ 

In the case presented here, the course of the right coronary artery was retrocardiac, the patient had no angina symptoms, and no evidence of stenosis or slow angiographic filling were found on coronary angiography. The patient underwent successful mitral valve repair without surgical intervention on her coronary arteries. 

Conclusion

Single coronary artery with origin of the right coronary artery from the left circumflex artery is an extremely rare finding. This particular coronary artery anomaly can be associated with myocardial ischemia and increased risk for sudden cardiac death, particularly if the anomalous artery traverses within the aortic wall or between the aorta and pulmonary artery. 

This case underwent double-blind peer review from members of the Cath Lab Digest editorial board.

The authors may be contacted via Anjali Varma Desai, MD, at anjali.varma@nyumc.org.

References

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5. Yamanaka O, Hobbs R. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn. 1990 Sep;21(1):28-40.
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