Absent Left Main Stem With Unusual Morphology of Single Coronary Artery

An 82-year-old male presented with typical chest pain associated with mild troponin rise and lateral T-wave inversion on electrocardiogram (ECG). Coronary angiography (Figure, A–B) revealed absence of a conventional left main coronary artery from the left coronary cusp. There was a single coronary artery (SCA) with an aberrant left coronary artery (LCA) arising from a dominant right coronary artery (RCA). The aberrant LCA bifurcated in the mid-interventricular groove; one limb constituted the mid-to-apical left anterior descending (LAD) artery, the other limb extended retrograde and ultimately coursed a traditional left circumflex territory.