Anomalous origin of posterior descending artery from left anterior descending in the presence of a diminutive right coronary artery: diagnosed by ECG gated multi-detector CT.

Coronary anomalies are easily detected on ECG gated multi-detector CT which has shown to be superior to conventional angiography is demonstrating their origin and course. We present an unusual case of posterior descending artery arising as the continuation of the left anterior descending artery (LAD) in the presence of a diminutive right coronary artery (RCA). The LAD crossed over the apex and continued its course to the base of the heart in the posterior interventricular groove as PDA. The RCA, although normal in origin, was diminutive and terminated on the lateral wall of the right ventricle. This anomaly has been rarely reported and the previous cases have all been conventional angiographic findings.