Hyperdominant left anterior descending artery continuing across left ventricular apex as posterior descending artery coexistent with aortic stenosis

Abstract

We describe, in a 61 year old man, with coexistent aortic stenosis, the anomalous origin of posterior descending artery (PDA) from a stenotic left anterior descending (LAD) artery, as its continuation across the left ventricular apex, in the presence of a normally arising and atretic proximal right coronary artery. The patient underwent mechanical aortic valve replacement and triple coronary artery bypass grafting and made an uneventful recovery. To the best of our knowledge, origin of PDA as a continuation of LAD across the left ventricular apex in the presence of a normally arising but atretic proximal right coronary artery has never been described in literature before. There is one previous case report of continuation of LAD as PDA across the left ventricular apex in a patient with single left coronary coronary artery with an absent right coronary ostium. As the blood supply to the entire interventricular septum is derived from this "hyperdominant" LAD system, stenosis of LAD can be catastrophic. A review of literature of the anomalies of right coronary artery and, in particular, of its anomalous origin from LAD and its coexistence with aortic stenosis, is presented.

Figure 1

Aortic root angiogram showing normally situated left and right coronary ostia, normal left main stem and small, atretic right coronary artery.

Figure 2

Selective right coronary angiogram showing a normally situated coronary ostium, a small atretic RCA giving off SA nodal, right atrial and right ventricular branches and petering out thereafter.

Figure 3

Selective left coronary angiogram demonstrating normal left main stem and circumflex and continuation of LAD as PDA.

Figure 4

Bifurcation stenosis of LAD and Dx and continuation of LAD as PDA.

Figure 5

LAD continues as PDA and then as RCA rightward of the crux, where it gives off the left ventricular branch to the inferior surface of the left ventricle.

Figure 6

LAD continues across the LV apex as PDA.