Anomalous Left Circumflex Artery Arising From the Right Coronary Artery: A Cadaveric Case Report and Review of the Literature.

Coronary artery anomalies are relatively rare in the general population; however, they remain clinically significant due to their varying effects on cardiovascular function and diagnostic and treatment outcomes. Here is described an anomalous left circumflex artery (ALCx) discovered during routine dissection of a 76-year-old female anatomical donor. The ALCx was seen arising from shared ostia with the right coronary artery and conus artery from the right aortic sinus of Valsalva, giving off the left atrial branch along its retroaortic course before reaching the left aspect of the coronary sulcus. The left coronary artery took a traditional course, arising from the left aortic sinus of Valsalva before traveling in the anterior interventricular sulcus. A review of the literature was conducted to determine the incidence of ALCx and elucidate any associated clinical considerations. Though relatively rare, clinical awareness is necessary as evidence indicates ALCx, particularly the retroaortic portion, may be more prone to atherosclerosis, intimal proliferation, luminal occlusion, and increased ratio of necrotic core in atherosclerotic plaques. Imaging studies, including the aortic root sign on left ventriculography, can aid in the identification of ALCx. Awareness of ALCx and its potential influence on cardiac health is critical for the avoidance of diagnostic errors and adverse treatment outcomes. Through this case report, we seek to present the current evidence outlining the incidence of ALCx, as well as the literature surrounding its clinical implications.