INTRODUCTION
Variations in coronary anatomy are extremely common, including
alterations in left/right dominance, dual anatomy and recessive vessels.
For the left main stem (LMS), the commonest anomaly is either a short
vessel or absent vessel (i.e. the LAD and circumflex emerge as a
bifurcation at the left coronary ostia).
However, atresia of LMS is an extremely a rare condition: here, the left
system is supplied completely by the right coronary artery (RCA) via
retrograde collateral circulation. According to the literature these
cases present at a very early age with signs of heart failure, and
rarely in adults.