Eur J Anat, 22 (4): 355-365 (2018)

A morphometric anatomical study on the division of the left main coronary artery and myocardial bridges

Vu Hoang Nguyen¹, Ernest F. Talarico, Jr.²

¹Anatomy Department, University of Medicine and Pharmacy at Ho Chi Minh City, Vietnam, ²Anatomy & Cell Biology, Indiana University School of Medicine-Northwest, Gary, Indiana, USA

ABSTRACT The division of the left main coronary artery (LMCA) exhibits a range of anatomical variation. It can divide into two, three, four or five branches, and have myocardial bridges. This carries important significance in clinical practice. The objective of this study was to examine the morphometric anatomical variation of the LMCA in Vietnamese cadavers. Hearts from 125 cadavers preserved in formalin solution were used in the study. LMCA was present in 96% of the specimens with the mean diameter of 4.62 ± 0.74 mm and the mean length of 9.05 ± 3.61 mm. The LMCA gave rise to two branches (bifurcation) in 51.2%, three branches (trifurcation) in 43.2% and four branches (quadrifurcation) in 5.6%. The mean outer diameter of the anterior interventricular artery, circumflex artery and the intermediate branch were 3.78 ± 0.54 mm, 3.33 ± 0.67 mm, and 1.80 ± 0.62 mm, respectively. The anterior interventricular artery ended at the anterior interventricular sulcus in 1.6% of the specimens, ended at the apex in 21.6%, and crossed over the apex to reach the posterior interventricular sulcus and terminate there in 76.8%. The circumflex artery ended before the left border in 4.13%, at the left border in 46.28%, between the left border and the crux in 46.62% and at the crux in 4.13%. The myocardial bridge was present only at anterior interventricular artery in 41.6%; in both anterior interventricular artery and posterior interventricular branch in 5.6%. LMCA varies in length and it can divide into two, three or four branches. End position of the anterior interventricular artery and the circumflex artery are variable. These variations may prove challenging during percutaneous coronary intervention (PCI) or coronary artery diagnostic imaging.

Keywords: Left main coronary artery â?? Circumflex artery â?? Anterior interventricular artery â?? Intermediate branch â?? Crux