Dual left anterior descending coronary artery (type III) and the presence of myocardial bridges: A post-mortem examination

Abstract

An observational examination of the heart was performed in the Department of Anatomy, during the routine autopsy of an 89-year-old man. The heart was fixed in 10% formalin and an analysis of arterial vasculature was performed (used morphometric abbreviations below [mm]: L - length; D - diameter of origin). Trifurcation of the left main coronary artery (L = 17.4; D = 8.1) was observed during the study, which originated in the left aortic sinus and was followed by three branches: proper left anterior descending artery (pLAD; L = 11.2; D = 7.4), intermediate branch (L = 98.6; D = 3.5) and left circumflex artery (L = 104.2; D = 4.9), respectively. In the pLAD division, there was noted LAD1 (long) which was running in the interventricular septum (L = 32.2) and further in the subepicardial segment (L = 109.3) in the anterior interventricular groove towards the apex (AC) (LAD1; L = 141.4; D = 6.3) and LAD2 (short) running subepicardial in the anterior interventricular groove in the AC direction (LAD2; L = 68.4; D = 3.2). Four diagonal branches (DB) and 9 septal perforators (SP) were observed in the course of LAD1; regarding the LAD2 there were 6 SP only. It is worth noting that the first SP supplying the interventricular septum came from LAD2. Another interesting aspect of the observation was the occurrence of 4 myocardial bridges on the LAD1, LAD2, DB1 arteries and on the second obtuse marginal branch (OM2), respectively. This case describes a rare anatomical anomaly of the LAD course and reminds clinicians of the need for careful planning of cardiac surgeries and percutaneous interventions on the coronary arteries.