Coronary artery variation in a native Iraqi population. 
The variation and distribution of the coronary arteries were studied in 119 hearts of individuals, 4 fetal months to 40 years old, who died from noncardiovascular causes.  All individuals included in this study were natives of the Mosul area of northern Iraq.  The coronary arteries were examined by injection-corrosion and unaided dissection.  Almost all (90%) of the anomalies observed were in the right coronary artery.  Nine hearts (8% of total sample) possessed ectopic ostia in the right coronary sinus for the right coronary and conus arteries.  The occurrence of a separate conus artery appears to be anomalous rather than ubiquitous as widely reported in the literature.  One specimen had separate origins for the left circumflex and anterior descending arteries from the left coronary sinus.  The patterns of coronary artery distribution were classified as left (14%) and right (46%) preponderant, and balanced (40%), following Schlesinger [Schlesinger, Arch Pathol 30:403-415, 1940].  The present study adds to the growing body of data on intrapopulation frequencies of coronary artery variants among non-Europeans and supports the contention that postpartum development may modify the pattern of coronary divergence from the aorta.  As the number of non-Caucasian patients undergoing surgical treatment for ischemic or valvular heart disease increases, additional comparative data on racial, sexual, and ontogenetic variation of the coronary arteries and their aortic ostia are required to improve the care of these patients.