Morphological expression of the left coronary artery: a direct anatomical study.

The left coronary artery presents wide variability in its morphological expression. The purpose of this work was to determine the variations in the left coronary artery and those of its branches in heart samples taken from a group of 154 Colombian mixed-race people. Cadaveric coronary arteries were injected with synthetic resins. Left coronary artery trunks presented 6.48 +/- 2.57 mm lengths. Left coronary arteries were bifurcated in 80 hearts (52%), trifurcated in 65 hearts (42.2%) and tetrafurcated in 9 hearts (5.8%). A short circumflex branch was observed in 143 hearts (92.8%), finalising as a left marginal branch in 39 of them (25.3%). The inferior third of the posterior interventricular sulcus was the most frequently occurring segment in anterior interventricular branch finalisation (63.6%). The calibre of the left coronary artery trunk was 3.58 +/- +/- 0.59 mm, that of the anterior interventricular branch 2.94 +/- 0.5 mm and that of the circumflex branch 2.71 +/- 0.54 mm. Of the total sample 86 myocardial bridges were observed with 61 cases (70.9%) in the anterior interventricular branch, distributed amongst all segments (proximal, intermediate and distal). Average myocardial bridge length was 19.4 +/- 10.7 mm, and no gender differences were observed (p = 0.20). The most frequently occurring location of the myocardial bridges, on the anterior interventricular branch (proximal and intermediate), agreed with previous studies. Left coronary artery trunk length and calibre and that of its branches were considerably smaller than those reported in other populations. (