Branch location in the left anterior descending coronary artery and its relation to the known distribution of early atherosclerosis

The circumferential and longitudinal locations of branches were determined for 33 left anterior descending coronary arteries (LADS) from persons aged less than 40 years who had died of noncardiovascular causes. In 17, branch location was determined using digitized maps of opened perfusion fixed arteries. In the remainder branch location was measured directly from resin casts of the arteries. Branch location showed a fairly uniform longitudinal distribution throughout the LAD. In the proximal 3 cm of the LAD—the segment known to be principally involved in early atherosclerosis—the results indicate symmetrical distribution of branches, with origins from the posterior and, particularly, both lateral walls. This is in sharp contrast to the known distribution of early atherosclerotic lesions in this area, which occur mainly on the side wall opposite the flow divider separating the circumflex. This study suggests that these branches are not an important determinant for location of atherosclerosis in this site.