Anatomic variations of coronary arteries: origins, branching patterns, and abnormalities

Abstract

Abstract Background Anatomic variations in orifices, courses, branching patterns, and abnormalities of coronary arteries could affect blood supply, hemodynamic characteristics, and clinical symptoms, and could be a risk of atherosclerosis. Objectives To investigate the location and number of both coronary orifices in the aortic cusps, branching patterns of left main trunk, dominant pattern of posterior interventricular artery (PIA), prevalence of right posterior diagonal artery (RPDA), myocardial bridge, and other abnormalities. Methods We dissected 95 heart specimens from cadavers of Thai donors without the history of surgery, and the dominant patterns, location and number of orifices in the aortic cusps, branching patterns, origin and number of conal arteries, and occurrence of RPDA were determined. Results Dual aortic origin of the coronary orifice was the most common condition. Anomalous 2 orifices in the left aortic cusp were found in one specimen in which the right coronary artery (RCA) arose from aortic cusp and had an interarterial course. Right dominance and trifurcated form of left main trunk were found more frequently. Most frequently 2 conal arteries were found. RPDA was found in 45% and mostly originated from RCA. The prevalence of myocardial bridge was 62% and located mostly on the anterior interventricular artery (AIA). Conclusions The prevalence of right dominance, RPDA, the atypical origin of RCA from the left sinus, and the prevalence of myocardial bridges was more frequent than reported by others, whereas the dual aortic origin from both cusps and the prevalence of bifurcated left main trunk was less frequent.