The unusual variant coronary anatomy of a 54 year old man with angina is illustrated here schematically and angiographically. The right coronary artery (NR) was non-dominant. The circumflex artery (Cx) continued along the atrioventricular groove giving off the lateral circumflex (LCx) before passing onto the inferior surface and terminating as a vestigial posterior descending artery (VP). An aberrant vessel (AV) arose from the left anterior descending (LAD) distal to the first diagonal (D). This aberrant vessel passed anterior to the root of the main pulmonary artery and the right ventricle to reach the acute margin of the heart before passing onto the inferior surface and terminating as the main posterior descending artery (PDA). There was a significant stenosis of the LAD beyond the origin of the aberrant vessel and the patient received a left internal mammary artery graft to the LAD. The operative appearance confirmed the interpretation of the anatomy.
There have been less than 10 reported cases of the right coronary artery arising from the LAD. In all of these the aberrant vessel passed anterior to the root of the pulmonary artery, but unlike the currently described case they all passed along the right atrioventricular groove and none had an identifiable right coronary ostium.
Cardiac surgeons need to recognise such variant anatomy to avoid damage of an aberrant vessel by vent placement, and also to avoid misidentifying the LAD as the vessel that is sited furthest to the left on the anterior surface of the heart.
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