Single left coronary artery with separate origins of proximal and distal right coronary arteries from left anterior descending and circumflex arteries--a previously undescribed coronary circulation

Abstract

A single left coronary artery with right coronary artery arising from either left main stem (LMS) or left anterior descending artery (LAD) or circumflex artery (Cx) is an extremely rare coronary anomaly. This is the first report of separate origins of proximal and distal RCA from LAD and circumflex arteries respectively in a patient with a single left coronary artery. This 57 year old patient presented with unstable angina and severe stenotic disease of LAD and Cx arteries and underwent urgent successful quadruple coronary artery bypass grafting. The anomalies of right coronary artery in terms of their origin, number and distribution are reviewed.

Figure 1

Aortic root angiogram showing single left coronary artery and absent rightcoronary ostium.

Figure 2

Left coronary angiogram in LAO view showing anomalous origin ofproximal RCA from proximal LAD, proximal to LAD stenosis.

Figure 3

Left coronary angiogram in cranial view showing the anomalous origin of proximal RCA from proximal LAD.

Figure 4

Left coronary angiogram in RAO view demonstrating the proximally stenosed circumflex artery continuing as the distal right coronary artery after giving off the large obtuse marginal and posterior descending arteries.

Figure 5

The smaller anomalous proximal right coronary artery arising from LAD establishes an end to side anastomosis with the larger distal RCA arising as a cotinuation of the circumflex artery. The distal RCA beyond the anastomosis seems to meander along proximally.

Figure 6

The middle of the three right ventricular branches from LAD supplying the right ventricle. The anomalous proximal right coronary artery arose from LAD above this branch and is not seen.

Figure 7

The posterior descending artery is seen to arise from the circumflex. A smaller branch from the anomalous distal RCA, seen above the PDA in the picture, supplies the inferior right ventricular surface.