**6.2.4 Angiographic diagnosis of retroaortic course**

The LCA courses behind or beneath the aorta and emerges at the left atrioventricular groove. In RAO and LAO projections, the LCA passes posteriorly and downward (figure 17). During 30° RAO ventriculography, the mid LCA appears as a radiopaque "dot", posterior to the aorta.

Fig 17. Angiographic (right anterior oblique projection) view showing a retroaortic course of an ectopic circumflex coronary artery (arrow) arising from the right sinus.

orientation of the CX coronary artery is normal. The initial course of the LMCA is upward and slightly posterior in RAO and LAO projections (figure 16). During 30° RAO ventriculography, the distal LMCA appears as a radiopaque "dot", anterior to the aorta.

Fig. 16. Angiographic view (right anterior oblique projection) showing a preaortic course of a left main coronary artery (white arrow) arising from the right sinus with a posterior and

The LCA courses behind or beneath the aorta and emerges at the left atrioventricular groove. In RAO and LAO projections, the LCA passes posteriorly and downward (figure 17). During 30° RAO ventriculography, the mid LCA appears as a radiopaque "dot", posterior to the aorta.

Fig 17. Angiographic (right anterior oblique projection) view showing a retroaortic course of

an ectopic circumflex coronary artery (arrow) arising from the right sinus.

upward loop (star).

**6.2.4 Angiographic diagnosis of retroaortic course** 


Table 7. Main angiographic characteristics of ectopic courses of anomalous connections of the left coronary artery with the opposite sinus or contralateral artery. LAD: left anterior descending coronary artery.
