Summary

A single coronary artery (SCA) ostium is a rare finding. In the general population, the incidence of SCA is approximately 0.024%. We introduce a case of a warehouseman presenting with chest pain after a morning work. The exercise ECG showed ST segment depression in the V 1–4 leads. The coronary angiography procedure and the CT demonstrated an SCA dividing into the right coronary artery and left main coronary artery. We identified a borderline lesion in the distal left anterior descending artery with fractional flow reserve of 0.85. In our case, the coronary anomaly was considered at low risk of arrhythmia and sudden death, and the patient was, therefore, treated conservatively.